I had been using only 256 MB of RAM on my PC because I could not afford to buy anymore, however this past weekend I went and bought a 512 MB stick of a different brand, I moved the 256 MB to the second slot and used the 512 MB in the first, I put my virtual memory to double the amount 1568 MB, all was well. After I mentioned this to my girlfriend's dad he told me he had 2 512 MB Kingston sticks I could have, I thought awesome!, I will take out the 2 I have and put in the 512 MB Kingston's ( I only have 2 slots) So I took out the recently bought 512 MB Corsair and the 256 Kingston that came with my computer and put in the 2 512 MB Kingstons.(Booted up the computer and doubled the virtual memory to 2048 MB, I heard that doubling the amount for the virtual memory is good) This is where the trouble started. I did not know why because I did the same thing for the bigger memory, but I began using programs and after awhile they would stop responding, Windows Explorer shutdown and so did an AVG scan that I was running. The blue screen then appeared and said something to the effect of a paging error in a non paged area, and it recommended I restart if this was the first time I saw this message, it happened a second time and I looked at the other options, so I just took out the new memory and put in the old that added to 768 MB ( the Corsair and the Kingston) all has been working fine, that is currently what I'm using while typing this. It also said sometihng about disabling BIOS memory if that didn't work or something. Can anyone help me out? I'm decently tech savvy, but this is a bit over my head.