I have just built the pc this weekend
AMD Phenom II x4 940 cpu
4gb corsair ram
MSI DKA790GX Platinum mbd with on-board ATI Radeon 3300 graphics
Saphire Radeon HD4870 gpu
Antec 650w modular psu
Arctic Cooling Freezer 64 PRO PWM Fan
1tb samsung hard drive - new
250gb maxtor hard drive - from old machine
160gb samsung hard drive - from old machine
When I install the HD4870 the machine requires several attempts to boot and then usually hangs at the windows logo and reboots
Without the HD4870 and using only the onboard gpu the machine boots fine and seems to be working, but shuts down usually 10 or 15 minutes into any game I try to play such as World of Warcraft.
I have run speedfan and am averaging temperatures of between 25 and 35 during gameplay so the moment I don't think the cause is overheating
I would really appreciate any help to get my machine running at full spec with the HD4870 or even just being able to play games using the onboard gpu for now.