"If it's a damaged file system case then:-
1.Insert the Windows XP CD-ROM into the CD-ROM drive, and then
restart the computer.
Click to select any options that are required to start the computer
from the CD-ROM drive if you are prompted.
2.When the "Welcome to Setup" screen appears, press R to start the
Recovery Console.
3.If you have a dual-boot or multiple-boot computer, select the
installation that you must access from the Recovery Console.
4.When you are prompted, type the Administrator password. If the
administrator password is blank, just press ENTER.
5.At the command prompt, type chkdsk /r , and then press
ENTER.
6.At the command prompt, type exit , and then press ENTER to
restart your computer.
This takes a bit longer, but the system should boot back into
Windows."
err.. does this mean reformat comp?
No, it just tries to read data off the hard disk sectors that
went bad and place them in a working one. It's like you have a pill
box with many compartments, and if one of them was infested with
worms, you may try to take out whatever that is still edible and
place them in another compartment. The file system is like a piece
of note that keeps track of the pills in each compartment and is
stored in one of them as well. If the worms feed on that to scraps,
your pill box may very well become nothing more than a load of
junk. If some of your pills are rare and expensive, you may want to
consider bringing them to a pharmacist (professional disk recovery
service) to differentiate and pick them out, but it will lighten
your wallet by hundreds or even thousands of bucks to hire
them.
"/R
Locates bad sectors and recovers readable information."
- http://en.wikipedia.org/wiki/Chkdsk