Memory Type: DDR PC2700, DDR (ECC)
Maximum Memory: 12GB
In uni-processor configurations only slots 1-4 can be used, limiting the maximum memory to 8GB. In dual-processor systems, all memory slots can be used.
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