akhila akki :
my windows xp is not working and safe mode is also not working while using f8
Put your Win xp cd, boot from cd, go to repair console, log in, type chkdsk /r, hit enter. It will check your disk for any error, and will fix it. You will need to repeat that until you see message that ends without errors. Then try to boot. If still can't boot, you will need new install.