1. Take out the 2 x 256mb chips, and see if the system will run on just the 512mb stick.
Is the BIOS seeing the RAM? Usually during the POST you get a table that lists a bunch of stuff, like devices on the IDE channels, and the amount of RAM etc, also the memory test that counts up to the total amount of RAM, is all that seem correct?
Try re-seating the 512mb stick is #1 doesn't work.
If #1 works, put the two 256mb sticks back in, if you start having problems again with windows not correctly seeing the memory try running something like memtest86 |
