If you are using Windows Vista, then you should use the Windows Vista installation disc. Likewise, if you are using Windows XP, you should use the Windows XP disc.
To perform a repair installation take the following steps...
Insert you installation disc into the CD/DVD drive. Now, restart your computer. During the first few seconds of your computer's boot loader, you may select an advanced option using an F key. Typically, keys such as F2, F4, F12, and Del (Delete) are used to access advanced actions during boot. Pay close attention to any text during the boot and boot from your CD/DVD drive.
Note: You may see a message asking you to press any key to boot from CD, in this case, press any key.
You will see a blue screen, ignore any messages to install drivers. At the next dialogue, press Enter to setup Windows. Do not choose Repair. Then, accept the Windows license agreement by pressing Enter.
At the next screen choose the installation of Windows you wish to repair. There should only be one if you have only have one genuine installation of Windows on your computer. Press Enter
Windows will perform a few functions to prepare your computer for an installation of Windows and then perform an in-place installation of Windows repair system files. Follow the on-screen instructions to complete the installation and let me know how it works out for you.