If your OS is located at C: drive then you will have to use a bootable floppy or CD. After booting from floppy or CD,you can go to command prompt and them type format C: And if your OS is not located at C then you can do that while running windows xp.
Format the C: drive
Format and reinstall.
You have to find out where the BOOT.INI is. You might have two of them. If you have two of them you can format the d drive. If you have one on the disk d you have to use restoring CD to put BOOT.INI file on disk C. Again if you have BOOT.INI on c you can format d.
to format c: get windows xp setup disk and boot up using that when you get to the step where setup asks you to choose the partition to put windows on, choose c: (probably the first one) and hit the indicated button to delete the partition (i think it's L) after that do a quick-format with ntfs and your c: will have been formatted.
In Windows XP Go to: Start>Programs>Accessories> Command Prompt.At the command prompt enter: format c:/This will format and erase all of the data on the c: drive. If you also have a d: drive then do a format d:/ command before you do the format of the c: drive.Caution: be sure you want all of the data erased as this action is not reversable.
Go to run and type Temp then enter, a window will open that will show you active window.
DRIVE C IS KNOEN AS WINDOW DRIVE,SO ITS DIFFICULT TO HIDE DRIVE C.... but if you wnt to do so ,then install your window inanother drive......
If you have a PC running Windows XP or 98 have a look at the following link: http://www.bootdisk.com/pendrive.htm I have had sucess with method 2 and 4. If you need to format the USB flash drive from a PC running DOS I can not help.
You cannot reverse such process especially after you have installed the os. But if you remember the old partition size you can format the disk again, delete partitions which you don't need and create a partition which you want to have.
Just log in on one of the copy of Win XP and delete Windows folder of other installation. Keep the installation on C: drive.
you can't format the drive that you're running windows from while in windows. use the setup disk to run a recovery console and you should be able to format it from there using format c:
you cant just remove one...you would have to reformat the whole hard drive, wipe it clean and then reinstall a fresh copy of windows...