I have not installed any new hardware in over three months. All of a sudden the last couple of weeks, I have been having random Crashes. Now, lately, my machine crashes about 4 times a day. I just reinstalled windows on a BRAND NEW HD, and still the same issue. The last hardware change I made was adding more RAM. I did not know that your RAM should always be the same MANUFATURER AND SIZE. I previously had 512 MB of Samsung, and I bought a 1 GB DIMM from Best Buy. After I did that, my computer started locking up and freezing whenever I used Memory intense proggies like QuickPar. So I took the old DIMM out and left the 1 GB Recently. By I am crashing constantly, especially when I use memory intensive apps. I consistently get the same error message from windows: Error Caused by Device Driver. Can someone help me? I do not know what to do. I am not using any new fancy drivers, just up to date ones as far as I know.