Some very fine details are required.
1. The make, model, version, bios version of that Dell.
2. The make, exact model numbers of those 2GB memory sticks.
3. The BIOS settings for Vram and timing.
Sorry, its all very technical and the devil is in the details.
Be aware that many off the shelf sticks of RAM do this. I stick with Crucial when it matters.
I am attempting to upgrade my Dell desktop from 2GB to 4GB. I get the dreaded "Blue Screen" after the new RAM module pair is installed and the machine reboots. Dell has checked out all my hardware and even replaced the motherboard and CPU. Is there a problem with using more than 2GB of RAM while running Visa? My RAM configuration is a pair of 1GB RAM. The machine is relatively new and came Vista capable.