Home | Community | Calendar | Technology | Photos | Downloads | Links | Contact
OEM Windows Re-install
Instructions for installing Windows 9x from scratch on an existing computer
To begin with, re-installing Windows is a last ditch effort. Many things have changed since this document was originally written, not the least of which Windows 9x platform have become semi-stable. Also, many computers have bootable CD-ROMs installed, and do not require the use of a boot disk. If you bought your computer from a manufacturer, you may want to avoid this drastic measure until you have called your vendor, to be certain that your problem is not something that is easily fixed. However, this page has been hit enough times that it seems worthwhile to leave it available... good luck!

The procedure requires five steps to complete:
  1. Save files that you want to keep
  2. Check your OEM number and create a boot disk
  3. Boot from the floppy and clean off the hard disk
  4. Run the setup program
  5. Reinstall necessary drivers

    Details
  6. Save files you want to keep - everything will be erased from your hard disk! If you don't have it saved somewhere besides the hard disk, you will lose it!
  7. Did your computer come with driver diskettes for the devices on your computer? There should be at least one floppy or CD for the modem, sound card, video card, and CD-ROM. If you don't have any of these, the most important driver is for the CD-ROM... it is necessary for the installation of Windows. If you don't have one, I'll go over what to do in the 'creating a boot disk' section. After collecting those disks (hopefully), and saving any files that you want to keep onto floppies, store them for now. You can check your OEM number by opening the Control Panel, and the System icon. The number should be displayed - it is under the General tab. You must have this number to install Windows - write it down if you can't find your Certificate of Authenticity. Next we can prepare the boot disk... if your computer or copy of Windows came with a boot disk, you can skip down to number 9.
  8. Create the boot disk.
    1. Insert a new floppy, or at least one that you don't need to keep.
    2. Open My Computer, right-click on the floppy drive, and choose format. You should get a window that gives you format options. The bottom check-box is 'copy system files'. You want to check that. That option copies the boot files onto the floppy. Click the start button. When it is finished, you have a clean, formatted, bootable disk.
    3. Close the format window, and open the c: drive icon. Find the Windows folder and open it. Find the Command folder and open it. Find the file format.com, and right-click on it. Choose 'send to' and then '3 1/2 floppy - A:'. That will copy the file to the a: drive. Now do the same with the following files: fdisk.exe, mscdex.exe, scandisk.exe.
    4. The last thing that you need to do for your boot disk is find the CD-ROM driver and change the startup files. Close the Command folder and the Windows folder. In the C: drive folder, look for the files Autoexec.bat and config.sys, and send them to the floppy disk the same way that you did above. These are configuration files that are executed every time your computer is started. We are going to change them to tell your computer to load the CD-ROM driver from the floppy.
    5. Close the c:\ drive window, and double click on the a: drive icon (in My Computer) to look at the files on your floppy.
    6. Right click on the Autoexec.bat file, and choose edit. Somewhere in this file, you may see the command 'c:\... \mscdex.exe /d:...' the '...' indicates some text that could change from computer to computer. After the '/d:', the name of the CD-ROM driver is given, make a note of it. Delete everything on this line before the 'mscdex.exe' - the line should now look like 'mscdex.exe /d:cdromname'. All of the lines after this one can be deleted as well (your autoexec.bat file will wind up with just this one line in it). If you don't have this line, add it, then save the file (file, save) and exit.
    7. Right click on the config.sys file - make sure that you are still editing the file on your floppy disk, and choose 'open with...'. You are presented with a list of programs that you can use to open the file. Select the notepad program to edit it. Look for the line that has your CD-ROM driver in it. There will be a line that looks like 'Device=c:\somefolder\somedriver.sys /d:cdromname', where cdromname is the same as was in your Autoexec.bat file. Choose 'My Computer' from your taskbar, and open the C: drive again. Open 'somefolder', and send the 'somedriver.sys' file to your floppy. You are copying the CD-ROM driver to your a: drive. Now close the 'somefolder' and the c: drive folders, so that you are back to the config.sys file that you opened with notepad. Delete all other lines in this file except for the line that has the CD-ROM driver in it. Delete the 'c:\somefolder\' part out of the line, so that it looks like: 'device=somedriver.sys /d:cdromname'. If your config.sys does not have the cdrom driver line in it, you will need to obtain a the driver from your cd manufacturer's website, or find a generic cdrom driver from a major manufacturer like Teac or Mitsumi. Once this is completed, you are in business! Save and exit notepad, and close all other open windows.
  9. Leave the floppy in the a: drive, choose 'Start', 'Shut Down', 'Restart the Computer'. Your computer should boot from the a: drive, and come up to just a DOS screen. That means a black screen with a DOS prompt. You should be able to watch the CD-ROM driver loading - this will tell you what letter your CD-ROM is, usually d:.
  10. Once the system has booted, type dir and press enter. This should show you a list of the files on your floppy drive - all of the files that you copied to it. Make certain that you have the Windows95 CD in the CD-ROM, and change to the CD-ROM by typing d: (or the letter that you saw as the CD-ROM driver loaded) and pressing enter. Type dir and press enter. This should show you a list of all of the files on the CD-ROM.
  11. If everything works, and you are certain that you have all of the files from the computer that you want, you can clear off the drive by changing to the a: drive and typing format c: and pressing enter. You will receive a warning that this command will erase all data from your hard drive. If you are certain that you are ready, press y for yes, and wait for the formatting to complete. This can take awhile.
  12. Next, copy the CD-ROM driver files to the hard disk by using the copy command. Type: copy Autoexec.bat c: and your Autoexec.bat file should copy, and the computer will say 1 file(s) copied. Do the same with the config.sys file, the mscdex.exe, and the CD-ROM driver file (the somedriver.sys file). Now change to the CD-ROM by typing d: and pressing enter. Start the Windows95 setup process by typing setup and pressing enter. Follow the prompts on screen to complete the installation.
  13. Pat yourself on the back.
Last Updated 12/2004