My computer is a great computer but recently it has been getting laggy and slow. I have cleaned all kinds of stuff off and defragmented it. I have a Dell Dimension 5100 with a Radeon x300,x550,x1050 series and only 512mb of ram. It has an Intel Pentium 4 CPU 3.20GHz Processor. I would like to upgrade my Graphics card from my old Radeon to the ATI Radeon HD 5550 Graphics. As for the ram i would like to get 2 more gbs of ram. The only memory sticks that fit into my computer come in only 1gb. Will this work in my computer?