How do I tell what type of RAM will work in my computer?

I have a Dell Dimension 3000 Desktop PC. I have (2X256MB) of RAM in there now and I want to upgrade it. How do I tell if it can support 2GB of ram? And how do I tell what RAM will work with it? I am looking at these 2 and were wondering if either would work with it.

http//www.newegg.com/Product/Product.asp?Item=N82E16820145074

http//www.newegg.com/Product/Product.asp?Item=N82E16820145085R

Use this tool http//www.crucial.com/systemscanner/

It tells you what type of RAM you need, how many slots are open, etc.

Edit Neither of those would work. You need

http//www.newegg.com/Product/ProductList.asp?Category=17&N=2010170147+1052107965+1052407860&Submit=ENE&SubCategory=147

thanks.. I see PC3200 will work but will PC2 3200 work? What is the difference?

[quote43da728239="BD2006BD"]thanks.. I see PC3200 will work but will PC2 3200 work? What is the difference?[/quote43da728239]

No, there is little difference as far as I am concerned, but PC2 is for DDR2 supported motherboards. I might be wrong on this though.