I am extremely novice when it comes to computers but I am trying to figure this out because I need faster speeds lol. So my understand is that my CPU ASROCK N68C-S UCC is compatible with G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model F2-8500CL5D-4GBPK. The current RAM in my CPU is 2 Samsung 1GB 1RX8 PC2-5300U-555-12-ZZ. Should I replace the old RAM with the new RAM since the brands are different or can I add the G Skill memory in addition without any problems? Thanks for listening.