I have installed redhat7.1 and windows2000 in my PC. I set a user profile when installing linux and set /home to a logical disk. Then I restart the machine and format that disk as FAT file system in Windows2000. Then I went back to linux and realized that I lost the user profile since I formatted the disk. I login by root and found that I can not save a user profile when creating a new user. The system would report the permission error when creating user profiles. So I ended only with the directory name in the /home. I appreciate any help that could lead to solve my problem.

You must look the /etc/fstab file. This file will have a entry saying file system and other info for the disk partitions.
Remove the entry for /home (save a copy )
Do a
mount /dev/xxx /home

, where xxx is your disk device (hda2, ...) that you have formated FAT in w2k.
Then

cat /etc/mtab

You will find the entry for this disk and will have fat as filesystem.
Add this line to fstab (see man 5 fstab and add 1 2 to the end of the line).
What do you want to say here ?

reader