Can I upgrade to 8gb on factory build XPS 420

[seakay]

Hello,
I have a XPS 420 with 4gb memory. Is it upgradeable to 8gb? Not sure as to the MB, how do I find out what it is? Any input is appreciated.

 

[cdabc123]

open the case see if it is ddr3 or ddr2 and if their are open spots for it

 

[seakay]

How do I tell the difference?

 

[cdabc123]

look at what it says on the ram it should say something like pc3. if it doesn't, look at the ram. if the notch is between the first 4 chips and the second 4 chips its ddr2. if the notch is somewhere between the first 4 chips its ddr3. the notch is much closer to center on ddr2.