0x00000050: PAGE_FAULT_IN_NONPAGED_AREA
(Click to consult the online MSDN article.)
Requested data was not in memory. An invalid system memory address was referenced. Defective memory (including main memory, L2 RAM cache, video RAM) or incompatible software (including remote control and antivirus software) might cause this Stop message, as may other hardware problems (e.g., incorrect SCSI termination or a flawed PCI card). Use the General Troubleshooting of STOP Messages checklist above.
You receive a Stop 0x00000050 error on a Blue Screen {KB 894278} Win 2000, Win XP, Server 2003 (with concurrent 1003/System entry in Event Viewer: possible Rootkit spyware infestation)

проверь ОЗУ и на вирусы Rootkit spyware