I have Dell Dimension 3000 2.8 GHZ Pentium 4, with 2*256 333 Mhz DDR SDRAM. I want to upgrade to 1GB but wonder whether there are cheaper deals than the Kingstons advertised by Dell. 4 questions: Do I have to have SDRAM or are other types of RAM OK (I don't know the difference)? Do I have to stick to 333 MHZ RAM - I note that some versions of the same computer seem to have 400 MHZ? Can I do this in stages, replacing one 256MB with one 512 MB at a time? Is this as easy as I am told or is there something else I have to worry about...? Any suggestions as to where to buy more cheaply? Thanks for any help.