This occurs because the loss of Ntfs.sys file in the folder c: \windows\system32\drivers, or there is a change so that the operating system can not run or hang. steps to fix it, do the following: 1. Booting the computer do the Windows XP CD. 2. Go to Recovery Console by pressing 'R' on the first screen. 3. go into the directory C: \. 4. Type the following command at the command prompt: copy D: \ i386 \ Ntfs.sys c: \ windows \ system32 \ drivers note - D: \ i386 \ Ntfs.sys here please adjust your cdrom driver 5. Once the file is successfully copied, remove the CD and reboot your pc. May be useful.