Blue screen

[#1]

I was having blue screen problems with an NEC Powermate computer and decided to format the drive and re-install using the provided system recovery discs
Everything appeared to go fine, I re-installed all important programs
System was running well
Then When I removed the last disc of a program I was uploading a new blue screen appeared
It showed IRQL_NOT_LESS_OR_EQUAL
and further down
Stop: 0xxxxxxxA (0x0012EF34, 0x000000IC, 0x00000001, 0x80502000)
Could anyone please shed some light on the cause and possible solution to this problem.
Thanks

[#2]

http://support.microsoft.com/kb/314063 may be worth a read to start with.
An 0x0A error (IRQL_NOT_LESS_OR_EQUAL) is *usually* hardware or driver related.
As the link suggests, try starting the machine with everything unplugged except the keyboard and mouse (this includes scanners, printers etc).
If the error still persists, try downloading http://www.memtest.org/download/1.70/memtest86+-1.70.iso.zip ;
Unzip it, and burn the ISO onto a CD, then boot off the CD and let it run its memory tests.  This may highlight a hardware problem with the installed memory.
If none of that works, post back!
B.