Ok I was going to upgrade my old dimension 4600 but the parts were getting too expensive and it wasn't worth it so I think I'm just going to build a computer. I'll probably start buying parts in January. Most of my time is spent using the internet and I might do a little gaming (Sims 3, Mirror's Edge, Batman Arkham Asylum, Prince of Persia, Burnout Paradise etc) I have a mouse, keyboard, 17 inch moniter, and speakers. Right now my resolution is at 1024x768 but it can go up 1280x1024. I'm not going to be doing any overclocking. I only want to spend maybe $400-$500. So far I have my CPU, Motherboard, RAM, Hard Drive, and PSU so I just need help finding a case, a good optical drive, and a video card.
Asus P5KPL-AM SE Motherboard with Intel Pentium Dual Core E2200 Processor w/ Fan Bundle
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4899657&CatId=3365
4GB kit (2GBx2), 240-pin DIMM, DDR2 PC2-8500 memory module
http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=5D2441BAA5CA7304
Western Digital WD3200AAKS Caviar Blue Hard Drive - 3.5", 320GB, 7200rpm, 16MB, SATA-300, OEM
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3179250&CatId=2458
Silencer 420 ATX
http://www.provantage.com/pc-power-cooling-ppcs420x~7PCPW005.htm
Asus P5KPL-AM SE Motherboard with Intel Pentium Dual Core E2200 Processor w/ Fan Bundle
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4899657&CatId=3365
4GB kit (2GBx2), 240-pin DIMM, DDR2 PC2-8500 memory module
http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=5D2441BAA5CA7304
Western Digital WD3200AAKS Caviar Blue Hard Drive - 3.5", 320GB, 7200rpm, 16MB, SATA-300, OEM
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3179250&CatId=2458
Silencer 420 ATX
http://www.provantage.com/pc-power-cooling-ppcs420x~7PCPW005.htm