Code:
BugCheck 1A, {41284, fffff7063fbcc001, 21e54, fffff70001080000}
Probably caused by : ntkrnlmp.exe ( nt! ?? ::FNODOBFM::`string'+4ac3 ) Code:
Usual causes: Device driver, memory, kernel
Follow these steps -
Test for any corrupted
drivers, by running Driver Verifier for
least 24 hours, stop the test if a BSOD occurs before this time frame. Driver Verifier will place stress on the drivers within your system, which will cause corrupted drivers to crash and hopefully be pinpointed.

More Help and Information with Driver Verifier -
Using Driver Verifier to identify issues with Drivers
Memory:
Run Memtest86+ for
least 7-8 passes, and preferably overnight as it can take a while to fully complete.
Test each
RAM stick individually, if an error is found then move the same RAM stick into the next DIMM slot and test again, if errors are found for the same RAM stick in every available slot then you have a faulty RAM module. On the other hand, if no errors are found in the next slot or the other slots for the same RAM module, then you have a faulty DIMM slot.
Test each RAM stick and every motherboard DIMM slot available.
Scan for any missing, modified or corrupted
protected Windows files with:
Did you buy a clean Windows 7 DVD or was it a Windows System Builder disc?