I have a tx2500 with 4GB RAM installed, Windows Vista Home Premium 64-bit, RM-70 (2Ghz) and all the other things the tx2500 has like the HD3200,etc. I noticed a while back that even though I have 4GB RAM, my TOTAL USABLE RAM is 2812MB, this sounded a little low but at the time I just blamed the integrated graphics because in Catalyst Control Center it says that the HD3200 is using 1470MB of the RAM. However if you add these together 2812 + 1470 = 4282MB, now it obviously can't be the graphics card using up the lost RAM since 4GB is only 4096MB. The only reason I got 64-bit Home Premium was so that I could actually use all 4GB of RAM but I can only currently use 2.75GB, this is really annoying! I've run memory tests and the RAM is OK, what could be causing this? Please tell me there is a fix! This is a clean install. I took out the RAM and inserted only one 2GB stick at a time and in both cases the TOTAL USABLE RAM was 1788MB and the HD3200 was using 958MB. Now one should expect that if both cards were in you would get double that, i.e. 3.5GB (3584MB) RAM and 1916 MB for the graphics to share. Please help! I had this laptop imported from America because I live in South Africa and there are no tablet PCs here. The RAM is fine, I have a 64-bit Operating System, what could it be? Something in the registry perhaps, or is this common in tx2500s? I saw another user in a different thread who said he had 4GB installed but only saw 2812MB as usable as well. I just want to sort it out, thanks for the help!