I had the same trouble - OK with 512, the minute you upgrade, windows crashes! The ram was good quality and matched, didn't matter. The RAM worked fine on everyone elses computer!!!!
In the end I gave up because it is now a spare, but, have you tried a BIOS update?
I'm about to, when I get around to it, but, there are 5 computers in the house and environs, so I haven't been rushed......after a year.......
“- He felt that his whole life was some kind of dream and he sometimes wondered whose it was and whether they were enjoying it.”
Bookmarks