Hi I am new to the forums but I am desperate for help. I have just built the following computer: Abit AN8 Fata1ty motherboard Athlon 64 3800+ 2 x Corsair Value select 400/3200 1gb ram modules Ati Radeon X1800XT 512mb 250 gb 7200 rpm SATA HD (Maxtor) Running WinXP 64 trial 550w power Latest ATI drivers Latest Nforce 4 drivers Latest sound drivers Latest AMD 64 processor driver The rpoblem I have is that the computer crashes whenever I ty to do anything remotely 3d. I have tried 3dmark 01 /05 and they both crash - mainly forcing a restart of the system, but sometimes just returning to windows. I cant play any games without it crashing during startup. I have tried turning off CCC, and using Ati tray tool, and using rivatune to turn my fan to 100% to keep the GPU temp down, thinking it would be an overheat issue, but still the same result. I am truly at m wits end as I have spent 3 days trying to get it to run. the farthest it has gone is to the end of the 3rd test in 3dmark05 before crashing. I have even tried swapping the memory about all temp ranges through out the system are perfectly fine, and I have tried previous drivers with and without catalyst. The only strange thing I can see is that in catalyst is that it lets the core clock be selected to 5000, obviously I'm not gonna do that though! Even as I ave ben sitting here, the computer has powered off from windows! I have built this rig for gaming, but cant play any games on it.... -HELP HELP HELP PLEASE PLEASE PLEASE!