Hi,
Before you think about reinstalling windows or even doing a windows repair from your windows CD try repairing it from the repair console.
1. Insert the Windows XP CD into your CD drive and restart your computer. If you are prompted, select any options required to start (boot) from the CD.
2. When the text-based part of Setup begins, follow the prompts. Select the repair or recover option by pressing R.
3. When you are prompted, type the Administrator password.
4. At the command prompt, type chkdsk [drive:] [/p] [/r]
drive: = This is the drive letter of the partition you want check for errors.
/p = This option instructs chkdsk to perform an extensive check of the drive and correct any errors.
/r = This option instructs chkdsk to locate bad sectors and recover any readable information from them.
Note: When using this option, the /p option is implied so it's not necessary to use it in addition to /r.
Chkdsk Command Examples:
chkdsk
In the above example, since no drive or additional options were entered, chkdsk simply displays the status of the current drive.
chkdsk c: /r
In this example, the chkdsk command is used to perform an extensive check of the drive to correct any errors and to locate any recover information from bad sectors.