Thanks ... for some reason the Crucial scan said it can only go up to 1G (2 512 modules) but the toshiba specs says it will hold 2 x 1GB.
While we're at it, my desktop is running 2 x 2GB = 4GB. There are four slots so I'm thinking of adding 2 x 2GB more. I'm running win 7 x64 and an AMD 64 x2 duo core. This should be ok, right?