Hello Chuck!
The Stop error related to the Blue Screen would really help us in differtiating the problem.
Since I am not aware of the error code, I would suggest you to try two steps.
1. Check for the actual amount of RAM shown in the BIOS.
2. Run diagnostics on Memory (which is a new feature in Vista)
3. Since the RAM is 3 Gig, I assume that you have {(2 x 1)+(512 x 2)} Gig RAM...
-->Try booting the system with Individual sticks.
-->If you don't receive the Memory error, then try booting the system with different combinations of RAM...(Make sure that you boot the system with the alternate slots filled with same amount of RAM, when trying combinations).
This will actually differentiate the cause for the problem.
Feel free to write for any further clarifications.
Provide the stop error for the BSOD, incase you have sufficient time to make a note, while the error appears.
Regards,
Chaitanya.
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