
Memory Type: DDR PC2700, DDR (non-ECC)
Maximum Memory: 512MB
Slots: 2

Only one of the sockets is user accessible.
The standard memory is installed in a socket which cannot be accessed by the end user. The second memory socket supports the end user upgrades. In order to reach the maximum you may need to have the standard memory replaced by an authorized service center

How much memory your Windows OS will recognize depends on which version of Windows you are running. 32-bit versions of Windows will see (and utilize) only 3GB or 3.5GB. To utilize more memory, install a 64-bit version of your OS. More information about OS memory maximums can be found here.

Memory or DRAM is the "working" memory of the computer. It's used to store data for programs (sequences of instructions) on a temporary basis.

video - installing memory