Memory is an integral part of every computer. Bad memory = Bad computer. This type of memory is not the kind you save to. The computer uses this memory as it sees fit. When selecting memory, look at the motherboard you are getting and buy the fastest memory the motherboard can take. (Memory is faster by it's rating: PC2700 is slower than PC3000). Only then will you know you're computer won't be suffocating on memory. Computers need at least 256MB, but it would be advantageous to get a single stick of 512MB. This allows you to put in more memory later.

512MB Corsair XMS CAS-2 with Heatsink