Blue Screen after upgrading memory to 256mb

I have a HP Pavilion xe783, I attempted to upgrade to 512 mb with 2 mb memory chips. They both work 256 mb work with the 128, but will not work together for the max. upgrade of 512 mb, windows will not load and I get a blue screen. I looked into overclocking, pretty much got me lost, someone said to change the bios but didn't explain how the 2 chips are kvr133x64c/256
and KVR133Q/256/R they should be campatible. Any help would be great

 

http://www.smartcomputing.com/messa...=&searchtype=&df=&dt=&sort=&cmd=&pg=53&uname=

 

i have the same problem.one memory stick will work without the other 256mb.Does anybody have a solution ? i have a pavillion XE783.

 

What options do you have in the BIOS ? Look for memory timings/settings