Assalamualaikum wr.wb,
THIS IS THE TUTORIAL USED TO REINSTALL YOUR WINDOWS WITHOUT USING CD.JUST U NEED TO DO IS DO BACK UP OF ALL YOUR WINDOWS CD. IN THE DRIVE WHICH YOU ARE GOING TO REINSTALL.

How To Reinstall Windows Without Losing Anything Here Is Another Possible Solution: easy way and tested:

1- Start Windows XP
2- Go to the location of your source files
3- Run WINNT32 /unattend
For example, D:\I386\winnt32 /unattend ( copy & paste this command into the RUN box, then press ENTER ) Your computer will do the rest.
Or,
Start > All Programs > Accessories > Command Prompt.
Copy & paste > D:\I386\winnt32 /unattend
Press Enter.
If you have i386 on your drive, you can replace D: ( if D: is your cd drive ) with the location of it.
I've often need to do this to repair something that had gotten corrupted and didn't want to do a clean install.

D: is the driver letter where your windows XP Cd is
if D:\I386\winnt32 /unattend doesn't work then try : d:\winnt32 /unattend.