Operating Systems

Computer Training Excuses - No ExcuseYou wouldn't go to a doctor who had never been to medical school, or hire a lawyer who never studied law. One side-effect of a world advancing as rapidly as ours is that fields are becoming more and more specialized and narrow. People can no longer get by on general knowledge in their careers, something I found out for myself not too long ago. I'd been out of high school for two years, scraping by on my own and picking up scraps of programming as I went. I saw all of the self-taught programmers breaking into the IT industry, and I hoped to do the same. After all, IT is one of the few industries out there where being creative and a quick learner is more important than a degree.
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First Batch Tutorial - First Batch TutorialThis small BATCH tutorial will become your door-way to becoming a good batch files creator or even a great one. Batch files make our lives a bit easier without a doubt. Learn how you can create your batch files within minutes. No experience needed.
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DOS Tutorial: The Basics - MS DOSThis DOS tutorial will completely get you off the right way if you're new to DOS. Remember, DOS is "not dead". It's just been tucked away under the carpet as the newer versions of Windows keep rolling out the assembly line. However, DOS is still an excellent choice to automate tons of chores.
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PowerShell: Windows Command Line on Speed - PowerShellWho needs another shell? Unlike the Unix world, Windows hasbeen pretty consistent with the shell environment. First there was MS-DOS (COMMAND.COM) and later Windows NT (CMD.EXE). You can actually still get to COMMAND.COM if you really, really want to. But for all intents and purposes, these have been the only two shells Windows users have ever known.

Microsoft wants to change that. When .Net was announced in 2000, Microsoft promised everything would one day be .Net. Unfortunately, Microsoft stuck the .Net name on things that were not .Net at all, such as Passport.Net which had no managed code in it at all.

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Batch Scripting on Windows 7 - Windows 7 Command LineThere are numerous reasons that batch scripting can help users get a more full experience out of Microsoft Windows 7. They can be used to automate tasks just as easily as they can contain long commands that are not easy to work around. By starting with more simple models, a programmer can usually get the feel for what batch scripts are supposed to look like. That being said, anyone who has some experience with the command line can essentially take a group of commands that they've entered and use them as a makeshift batch script with no further editing.
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Executing a Batch Script Within a Batch Script - Command PromptDo you like tinkering with Windows Command Line? It is an awesome way to learn batch scripting. But at times you may have a series of batch files that you would want to run or execute. Well, many folks do not know but there is a method that is used to do exactly that.
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MS-DOS Command Line Tutorial - MS-DOS Command Line TutorialWe bring to you small MS-DOS tutorial. A list of all the MS-DOS commands that we know of compiled into one easy to read list. If there is anything bugging you with DOS commands or if you've been looking for that one particular command that you needed and couldn't remember?
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Ma' Little Batch - batch file I wanted to take bit of time to introduce you to Batch Scripting in Windows environment. If you have no idea what Batch Script is, then this is for you. Keep an eye out for Batch Scripting Tutorials and Scripts soon to come.
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Remove Links Folder from Favorites - Remove Links Folder from Favorites Have you ever had that eye sore (Links Folder) that just wouldn't delete from your favorites list in IE browser? Or maybe, you delete it and it comes back the next time your computer turns on? Then this tutorial is for you!
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Why Programmers Love the Night - Programming at night One famous saying says that programmers are machines that turn caffeine from coffee and Coca Cola into a programming code. And if you ask a programmer when does he like working the most and when is he most productive - he is probably going to say late at night or early in the morning, that is when he has the greatest energy and concentration to work.
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Second Batch Tutorial - Second Batch TutorialToday you're going to learn how to make a simple "operating system" using batch tutorial. You'll learn about the following commands and features: echo, cls, choice, if, errorlevels, and labels. Once you've finished, you will have a batch file that can show a few different menus, enter into the menus and display the options contain within, and let the user pick the option they want. The example we are going to use is going to let the user choose which game they want to play.
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Third Batch Tutorial - Third Batch TutorialThis week you're going to learn the continuation of the second batch tutorial, which demonstrated how to make a simple operating system using batch files. If you are running Windows XP, some of the commands shown in this tutorial will not work. You will need to work through this tutorial on a computer running Windows 98 or plain DOS.
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Short Introduction to Operating Systems - Operating systemsWe at TW were browsing about the web when we stumbled upon Mark's work. Although it's much outdated, it's very fundamental. And please don't let the title fool you. This is not a small short article but a short OS introductory book. An operating system is a layer of software which takes care of technical aspects of a computer's operation. It shields the user of the machine from the low-level details of the machine's operation and provides frequently needed facilities
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Practical Batch Tutorial - Practical Batch TutorialThis tutorial was a long time coming. It teaches the readers in a very simple and down to earth language how to create a batch file to backup your various files. Also pushes the readers to think outside the tutorial and to figure out more ways to make the given commands even better. I suggest that anyone trying to learn Batch Scripting reads this. It will not be a waste of time, I promise.
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TW Tech Glossary - Misplaced your bible? Well here it is - Tech Glosasary! This truly took a while to complete and should be used by all from beginners to advance techies.
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How To Recover Deleted Files? - How To Recover Deleted Files?How many times have we come across TW visitor saying "How do I recover files" or "I deleted files from the recycling do I restore deleted files?"

Well, don't worry and be happy that you came across this little article on TechiWarehouse.Com.

You can often successfully recover deleted files from a PC, it all depends on what has happened since the files were deleted.

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Batch File Commands - Batch File CommandsThis is not a tutorial nor an article but a simple list of DOS Batch Commands. But it can come in very handy for anyone wanting to go into Windows Shell or Batch Scripting.
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What is Disk Operating System?

More commonly known as Microsoft DOS (Disk Operating System) is a command line user interface. MS-DOS 1.0 was released in 1981 for IBM computers and the latest version of MS-DOS is MS-DOS 6.22 released in 1994. While MS-DOS is not commonly used by itself today, it still can be accessed from Windows 95, Windows 98 or Windows ME by clicking Start / Run and typing command or CMD in Windows NT, 2000 or XP.


Don't Forget - Check Your Memory!

To check the available memory left on your machine, use the MEM command. Thereare several options available (depending on the version of Dos/Windows you areusing) so type


at the DOS prompt to see what kind of memory checks you can perform.

Forcing the Directory to Display a Certain Way

If you wish to set the directory listings a certain way (when you use the DIRcommand), set the DIRCMD environmental variable to the parameters you wish touse.

To see a list of possible parameters for the DIRCMD, see the list of possibleparameters for the DIR command. Type

DIR /?

To set the DIRCMD environmental variable, add the line


in your AUTOEXEC.BAT file, replacing 'xxx' with the parameters you wish touse. For example, the parameter "/ON" would cause your DIR results tobe automatically sorted by filename. The "/W" command automaticallysets the DIR results to a wide-directory format.

Use Your Up Arrow For Latest Dos Commands

The DOSKEY program is very useful for many reasons, but some people feel thatthey do not need its powerful features and fail to install it. If for no otherreason you should install DOSKEY, do so for this trick - with DOSKEY installed,using the up-arrow scrolls through your latest DOS commands. If you use DOS alot, this is a *lifesaver!*

Install DOSKEY by editing your AUTOEXEC.BAT file with EDIT or any other texteditor. Add the line "DOSKEY" or "LH DOSKEY" to the end ofyour AUTOEXEC.BAT file. If this fails to work, you need to add a line to the endof your AUTOEXEC.BAT file with the full path to the DOSKEY.COM program. If youare using Windows 95, DOSKEY.COM probably is in your C:\WINDOWS\COMMANDdirectory. If you are using DOS 6.xx or earlier, it is probably in your C:\DOSdirectory.

For example, if DOSKEY.COM is found in your C:\DOS directory, add a line tothe end of your AUTOEXEC.BAT file as follows:


DOSKEY takes up just a little bit of memory so if every byte counts, you'llhave to live without its usefulness.

Secret (?) Directories

Although this doesn't keep advanced users away from your files, when namingprivate directories, use this instead of a space: Hold down the ALT key whiletyping 255 from your numeric keypad. While this looks like a space, it isn't.

Backup your Configuration Files

Before you make any major changes or software installations, ALWAYS back up yourAUTOEXEC.BAT and CONFIG.SYS files. Many software programs will make updates tothese files without your permission, potentially causing many problems anderrors on your system.

Extended Pattern Matching

You may know that with just about every version of DOS, using the '*" in acommand matches all files which match the characters before the asterisk. Inlater versions of DOS, however, you can use the asterisk to select every filewhich matches the character after the asterisk.

For example, a DIR *EC.* in the root directory could match filesAUTOEXEC.BAT, AUTOEXEC.DOS, DUALEXEC.INF, and LEC.TXT. And yes, you can do apattern-match with characters before and after the asterisk.

Redirect the Positions of the Redirect

When you perform a command involving redirecting the output such as DIR *.TXT> TEXTLIST, you normally place the redirection symbol after the command youare redirecting. You don't have to do this. The command > TEXTLIST DIR *.TXTworks fine.

Need Quick Help on a Command

Do you need help on a DOS command (or a DOS command in Win3.1/95?) Depending onthe version of DOS you are using, either type in HELP and the command-name ortype in the command-name and /? to receive help on the command.

Another Way to Show Fragmentation

Instead of using DEFRAG, you can check individual files or groups of files tosee if they are fragmented. To do so, type in 'CHKDSK filenames', where'filenames' is a filename or group of filenames you would like to check.

For example, to check the GAMES directory for fragmentation in *.DAT files,type in this command.


CHKDSK will give you a report of each file's non-contiguous blocks. The morenon-contiguous blocks a file has, the more fragmented it is.

List Every File on Your Hard Drive

To list every file on your hard drive, you could pull out some combinations withDIR /S to show files in all subfolders, or you can just type in CHKDSK /V. Doingso will show every file on your hard disk, and at the end, will show you areport of the total disk space, total free space, and more.

Save this report to a text file for later viewing. Type in


Too Much Help

Have you ever performed a /? on a DOS command to view help, only to find thehelp scrolling off the screen? Don't panic. Just add '> txt' to the end ofthe command, and you'll find a textfile called 'txt' that has the contents ofthe help.

For example, to view the help on the DIR command, which under some versionsof DOS will contain enough information to fill up and scroll one screen, type inthis command at the prompt - "DIR /? > tmp" (without quotes).

Sort Order Shortcut

The help for the DIR command may be confusing regarding performing sorts. You donot have to use a colon in conjunction with the /O command to perform a sort.

For example, to sort files by size, DIR /OS works just as fine as DIR /O:S

Another way to REMark

Instead of using just the REM command to place remarks in batch files, you cando the following to make the batch file easier to read.

Use a semicolon as the first character of the remark line, then tab twice,type in REM, a space, and then your remark. Placing your comments in the middleof the line may make the file easier to read.

More Version Information

In later versions of DOS, you can use the VER /R command to show more versioninformation, including the DOS revision and where DOS is loaded.

Copy Command Shortcuts

To copy files, one would normally type in the following.

COPY sourcefilepath\sourcefile(s) destinationfilepath\destionationfile(s)

If you are currently in the source file path's directory, you probably knowthat you can skip that part of the COPY command. What you may not know is thatyou can do the same if you are in the destination file's path.

For example, say you are in the C:\BITMAP directory, and you want to copy allof the BMP files from the A: drive to C:\BITMAP. Instead of typing


You can just type


Display a Blank Line in a Batch File

Typing ECHO and just a space in a batch file does not display a blank line -just 'Echo is on' or 'Echo is off.' To display a blank line, type in ECHO and aperiod using no spaces in between- ECHO.

Implementing the WAIT Command in a Batch

Do you need a batch file that waits a certain amount of seconds? In somelanguages, the command would be WAIT, but batch files do not come with thiscommand. If you want to implement this command, create the following batch fileand name it WAIT.BAT.

@CHOICE /T:N,%1% > NUL

Now, in order to wait 10 seconds in a batch file, just call the WAIT.BATbatch file as follows:


Always Fail on Abort, Retry, Fail

If you always want a prompt such as "Abort, Retry, or Fail?" or"Abort, Retry, Ignore, or Fail?" to fail, use the /F command-lineoption when running COMMAND.COM.

Pausing Directory Listings

If you don't know how to pause a directory listing, add '/p' (without quotes)to the end of the DIR command. So, if you want to display the directory but youwant the output to pause after displaying a screen of text, the command is DIR/P

Turning off Batch File Output

There are two ways to turn off the output from batch files. Entering the line@ECHO OFF at the beginning of a batch file should turn off the display ofcommands. Some DOS commands will ignore this statement, however, and continue todisplay text. If so, redirect the batch file's output to a text file or 'NUL.'For example, to hide the contents of batch file RUN1ST.BAT, use this to executethe batch file.


You need to experiment with this. Some commands or programs may reactadversely to this output redirection, and some programs may ignore theredirection.

Create 0 Byte Place Holder Files

If you need to create files from a batch file that merely act as place holders(i.e. they take up no hard drive space, just space in the directory), use theREM command and redirect its output to a filename of your choosing. This can beuseful in case you have a batch file that works in many directories. You canhave the batch file put a placeholder in every directory it acts upon, allowingyou to see if the batch file worked correctly or not.

Need Quick Help on a Command

Do you need help on a DOS command (or a DOS command in Win3.1/95?) Depending onthe version of DOS you are using, either type in HELP and the command-name ortype in the command-name and /? to receive help on the command.

Emergency Scenario - Write Batch Files without Edit

OK, here's the scenario. You have a boot disk and you had to use it in order toset up a system. Now, you need to make a batch file for some reason (perhaps atemporary AUTOEXEC.BAT). But, you forgot to copy the EDIT program that would letyou type up a batch file. What do you do?

At the DOS prompt, type:


Type your batch file, line by line, pressing CONTROL-Z and then enter at theend of the last line.

Type very carefully. You will not be able to modify what you typed inprevious lines.

Double your Lines

Type the following in a DOS prompt to double the amount of lines:


If you are strictly running DOS, you must have ANSI.SYS installed. If you arerunning DOS underneath Windows, this should work.

Quickly Get COM and LPT Port Status

To get the retry and redirection status of your COM and LPT ports, enter thefollowing command:


Dos for Unix People

I use DOS a lot. I use Unix a lot. And, like others who use both OS's, Isometimes forgetfully type in the wrong command. I type in 'quit' when I mean'exit,' 'ls' when I mean 'dir', and so forth.

Why not create a few basic batch files in your root, batch, or commanddirectory that can help you out? Even simple one-line batch files like thefollowing may help when you want the computer to do what you want it to do, notwhat you tell it to do . Just type in these commands, substituting C:\with your batch file directory of choice.

echo @exit > c:\logout.bat

echo @exit > c:\quit.bat

echo @dir %1 %2 %3 %4 %5 %6 %7 %8 %9 > c:\ls.bat

Do you have other ways to make DOS easier for Unix people? How about theother way around? E-mail me at with your tip.

Rewrite the Master Boot Record

Ever need to rewrite the master boot record of your hard drive, due to areformat, virus, or partial hard drive failure? This command will do so:

FDISK /mbr

Find All Files Of A Given Type

Ever need to find all of your batch files on your hard drive? Or, need to findall of your text files? This quick batch file will let you type in the followingcommand:


And it will display all of your batch files. Type:


And it will display all of your text files.

Just create a batch file called FINDALL.BAT, consisting of just this line:

@dir /b /s *.%1 | more

Want to sort the results? Make FINDALL.BAT consist of this line:

@dir /b /s *.%1 | sort | more

View Files Without Extensions

You know that typing DIR *. and an extension name displays all filenames withsaid extension, so that typing DIR *.BAT displays all batch files, DIR *.SCRdisplays all screensavers, etc. What about when you want to display all fileswithout extensions? The following command does the trick:

DIR /A-D *.

Note that the /a-d modifier is needed, otherwise your list of files withoutextensions will also contain a list of subdirectories.

Rename All Files From One Extension to Another

(Note that this may not work on early versions of DOS, so experiment.)

If you ever need to rename all files in a directory from one extension toanother, for example, *.new to *.old, you can use wildcards with the renamecommand. In this example, the command would be:

rename *.new *.old

Removing Read-Only Property From All Files in Directory

I was recently asked how to remove the read-only property from all of the filesin a given directory. It seems that this person was copying a large number oftext and document files from a CD and all of the resultant files had the"R" property set. Luckily, changing this property for all files isquite easy.

To remove the read-only attributes of all files in a particular directory aswell as its subdirectories, the following command can be entered at the DOSprompt or in a batch file:

attrib -r DIRECTORY\*.* /s

Replace DIRECTORY with your desired directory. For example, if you arecopying files from a CD to the directory c:\cdfiles, after copying the files,the command to remove the read-only attributes would be:

attrib -r c:\cdfiles\*.* /s

Display ErrorLevel on the screen

Debugging batch files and need to see the error level results of every DOScommand echoed to the screen? Try this command:


This echoes the command processor with 'errorlevel' echoed to the screen.

Display Your Command History

Need to know the last few or so commands that you entered at the DOS prompt? Youcan do so by first installing DosKey. Then, just press your F7 key at thecommand prompt. You'll see the last few commands entered in the current session.Better yet, you can re-execute previously typed commands (save yourself thosekeystrokes!) Press F9, type in the number corresponding to the command that youwant to re-execute, and presto, that command is at your DOS prompt!

If you need to clear your command history, press ALT-F7.

Place Date and Time in the Prompt

Always looking around for the current date and time? Why not place it in auseful place, say, the command prompt?

Add this line to AUTOEXEC.BAT:

prompt Time: $t$_Date: $d$_$p$g

Make a Floppy Bootable

A boot disk is a floppy disk that contains, at the very least, an operatingsystem. Boot disks are useful in case of a hard drive failure. With a boot disk,you can place a floppy disk in your computer when it boots up and still haveaccess to your computer.

While I highly recommend putting more than just the basic operating system ona boot disk, such as useful batch files, useful commands, device drivers, etc.,the following line *will* make a floppy disk bootable:


Dos for Unix People

Unix users - still mistyping commands at your DOS prompt? Here are a few moresmall batch files you can enter to alleviate your pains. Just type in thesecommands at the dos prompt, substituting C:\ with your batch file directory ofchoice.

echo @%1 /? > c:\man.bat

echo @copy %1 %2 %3 %4 %5 %6 %7 %8 %9 > c:\cp.bat

echo @move %1 %2 %3 %4 %5 %6 %7 %8 %9 > c:\mv.bat

Did You Know?

  • Microsoft rewrote the files that made up DOS making them useless.

  • Microsoft bought the original 86-DOS code that became PC-DOS for the IBM-PC. DOS was not developed originally by the Microsoft group. Bill Gates (in his book The Road Ahead, 1995) recognizes Tim Paterson as the father of DOS. Paterson's version is called 86-DOS which was designed for the 8086 Intel processor, for the Seattle Computer Products. 86-DOS is referred to as QDOS (Quick and Dirty Operating System), which contained about 4,000 lines of assembler language code.

  • DOS was first marketed by IBM as PC-DOS with the original IBM Personal Computer on August 1981. IBM originally used the acronym DOS in the early 1960?s for their disk operating system for the 360 series computers.

  • DOS originally included BASIC (Beginner's All-purpose Symbolic Instruction Code). Later BASIC was replaced by QBASIC (Quick Basic).

  • Nowadays Windows 4.x does not include any programming language by default. QBASIC has to be copied from the Windows CD-ROM (D:\OTHER\OLDMSSDOS) to C:\WINDOWS\COMMAND.

  • MS-DOS (less than 5 MB) has not been marketed by Microsoft, since 1994. Microsoft opted to concentrate on the Windows graphical OS project in 1983 (marketed against Steve Jobs' Apple Macintosh, 1984).

  • Nowadays the "not needed" part of MS-DOS 7.x (about 1.7 MB) is partially included as part of the Windows 4.xx (Win 95/98) package. Many files had been deleted though.

  • The D:\OTHER\OLDMSSDOS (Old MS-DOS) directory on the Windows 4.x disk has 17 files. Note that there is no TREE, just DELTREE.

  • The MS-DOS operating system is the foundation of all versions of Windows. Windows 3.1 was the last version running as a system program running on the MS-DOS operating system.

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