It could have been caused by update KB977165.
Take a look at this: <a href=”http://benosullivan.co.uk/windows/how-to-fix-page_fault_in_nonpaged_area-stop-0×00000050-after-windows-update/”>How to Fix “PAGE_FAULT_IN_NONPAGED_AREA, STOP: 0×00000050″ after Windows Update</a>
If that doesn’t help, I would try removing all hardware devices (including CD/DVD ROMs) to see if that makes any difference.
If you have more than one memory module, I would remove all but one, and would try switching modules if the error persists.
Also, I would run CHKDSK /r from the recovery console again to see if it keeps finding errors.
One other thing to try would be disabling any unnecessary feature from the BIOS.