Here is the scenerio: Tyan MB - Trinity KT-A AMD Athlon 1700XP (1.44 mhz, I believe) 40GB HD Win XP Pro Micron 256mb sdram I started off with one chip of Micron 256 sdram. I wanted to add more. Purchased 512mb dimm (generic). Installed new chip, and in properties under My Computer, the specs showed 768 MB of ram. Then, the dreaded blue screen hit after a short period of time. At first I thought that the 512mb dimm might be bad. I took it out, and rebooted ONLY with the original 256 dimm, and all was well. I decided to experiment. I pulled the 256 dimm, and installed ONLY the new 512 mb dimm. It ran fine all on it's own. No blue screen and no errors. I extended the experiment to adding the 256 back in, but in the 3rd dimm slot, rather than in the second. Again, computer read 768 mb of ram, but got the blue screen. I know the new 512 mb dimm runs at 7.5ns, but I'm not so sure of the original Mircon 256 dimm. So, is this a compatibility issue between the 2 brands of memory, as being read by the MB?

The major difference between SDRAM modules is the performance, generally referenced as PC66, PC100 and PC133. You will need to ensure that the new memory module is 'backwards compatible' witht he performance of the Micron module. From what you have described your 512Mb module is not happy living with the Micron module and I suspect this is because their specifications are incompatible.

Brian, Thanks for the reply. To the best of my knowledge, both modules are PC133 compliant. Would you be able to be more specific when you say "backwards compatible" between the two modules? Thanks.

Just a thought. Try putting the generic in the #1 slot. Also check the BIOS memory settings to SPD or automatic.