I have Redhat Linux 8.0 on my PC. It was working fine till yesterday. Now when I boot it, it starts to check the partition
and stops there.

When Linux shuts down it sets records in each partition to indicate that the partition was umounted cleanly. Maybe you had a power failure, or booted without issueing a shutdown command so that the parttion was not umounted cleanly.

When Linux is booted it checks for clean umount records in each partition. If it does not find them it runs fsck against each partition to try to fix the file system. fsck usually works. Answer yes to any questions fsck asks you about fixing something in the broken partition. When fsck has finished fixing the partition(s) then boot will continue.

fsck stores any file fragments that it cannot identify in the lost+found directory.
So after boot finishes check lost+found.

If the partition is so badly broken that fsck cannot fix it then you are in deep trouble. You will have to reformat the partition using mkfs and restore its contents from your backup files. If you don't have backup files then you will have to reinstall Linux.

If you have a working Linux box available see:
man fsck
man mkfs

Otherwise use Google to find the man pages on the Internet.

Need more information.

Are there any error messages?

Does it say something about entering a password?

no it doesn't ask for any password .
It stops before coming to fsck

it shows my hard disk size & c/h/s parameters

then it says
partition check

hda::

and stops there

what filesystem were you using?
is windows on the same hard drive and it works fine?

ya i have win xp on same hdd & it is working fine

on linux i have ext2 file system

do you have a linux bootcd you can run fsck from?

maybe you got some windows boot virus that moved the
bootsector, and so it works in windows, but not in linux.