Advice Pro said:
I know because I can boot into Vista and read it at Start menu > Computer content menu > Properties. I already had 2 GB of memory, but different speed, 667 MHz and this new module is the 800 MHz. Also, the original memory isn't dual channel.
To start with, there's no such thing as dual-channel modules. Two or four modules always are required to achieve dual-channel operation. Now about your issue, did you install an additional 2GB module or did you replace the 667MHz module with the new 800MHz module? If both modules are installed, they should probably be in the black slots for dual-channel operation.