STOP: c000021a {Fatal System Error}

Hello, my friend have given me his Inspiron 700m to fix and I am stuck on how to repair it. When I turn on the system, the windows xp loading screen appears and then it prompts me with the following error:

STOP: c000021a {Fatal System Error} The Windows Logon Process system process terminated unexpectedly with a status of 0x00000000 (0×00000000 0×00000000). The system has been shut down.

He has datas that he want to back up before he wants to format the drive. I have tried the last known configuration, running the recovery console with Chkdsk /r /p , booting into safe mode, and I am running out of ideas on fixing it but I have yet on trying the Dr. Watson debugger which I am not familiar with. Is there any alternatives on fixing this problem? Will greatly appreciate your help.