A buddy of mine is having trouble with getting his computer to start, seems XP is damaged but I can't figure out a way to fix it. A blue screen appears after Windows load screen and reads "windows logon process terminated unexpectedly" etc. and then gives a stop code of c000021a along with 0xC0000135. The system will not boot into safe mode and I've already run a disk check so I'm stuck. He said the computer was idle when this happened but he suffered from a power outage recently while the system was running. Everything seems to be working fine but XP will not start... winlogon.exe or csrss.exe is probably broken; I'm not sure how to fix this without a repair install. Any advice would be greatly appreciated.