Help with Compatible Memory Upgrade for Dell XPS 420

[Liamb2005]

Can someone please help me, im wanting to upgrade the memory from 4gb to 8gb on my sons Dell XPS420 computer, i know its DDR2 but the rest of the info goes over my head, would really appreciate some advice

thanks

 

[Liamb2005]

Yeah thats the one, strange but different websites are saying different things, some like this one

http://en.community.dell.com/support-forums/desktop/f/3514/t/19288748.aspx

say its capable of 8gb and the 4gb limit is just down to 32 bit systems, no look on the support website either... any ideas guys ?