
Memory Type: DDR PC2700, DDR (non-ECC)
Maximum Memory: 768 or 1024MB
Slots: 1
Each memory slot can hold DDR PC2700 with a maximum of 512MB per slot.*
*Not to exceed manufacturer supported memory.

If you notebook has 256MB of non-removable memory then your maximum is 768MB.
If you notebook has 512MB of non-removable memory then your maximum is 1024MB.

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