thanks for your reply,
In case some one is facing similar problem try below options.
what worked for me is that I went to C drive(right click it) -> properties->tools->error-checking->click check .
(don't forget to check 1)automatically fix file system error 2)scan and attempt to recover for bad sectors ) took quite a long time to fix it.
also is this doesn't work for you insert your drive in some other PC and attempt trying this process other there.
sorry I did not manage to try solution given by kees_B (as was unable to find XP CD) so you can try this if above doesn't work for you.
I had Win XP sp2 and I recently installed a Win XP sp3 but before installing the new XP I was getting option to chkdsk but every time i skipped it and did not perform any disk check on my old XP(e.i sp2) but when I installed new XP sp 3 to my surprise I was still getting an option to chkdsk during start up,and when I carried out this chkdsk it showed an error "setupact.log cross linked..." and PC hanged...
1)now how should I get rid of this chkdsk which appears at every startup ? is there any file which I could edit manually to disable chkdsk ?
2)and why am I getting this msg even though I have formated the old XP and installed the new one ?