I recently built a computer using an Intel D915PBL mobo and a 3.0ghz P4 w/ HT processor (lga 775). I put 4gbs of RAM in there the first time and I installed WinXP SP3 (x32). It was only showing on the My Computer properties that I had only 2.87gbs? I know that I saw the bios read the 4gbs so I know my ram is working. I did a little reaserch and ppl kept saying that x64 OS's showed the 4gbs. So, I tried installing WinXP SP2 (x64). I did a fresh install by booting the disk 4rm the bios and installing the new XP on top of the hard drive that had the old Xp thus reformatting the hd and giving WinXP x64 a fresh installation. Guess what? It still only shows 2.87gbs of RAM on the My Computer properties. I don't know what to do anymore. Anyone know HOW to fix this? Thnx 4 reading.