My friend recently gave me a Gainward Radeon HD4870 since I'm very poor and can't afford a proper upgrade to my system.
I had an Nvidia GT 430 before this (Not a gaming card, I know I know, but I'm poor D so I had to clear out all the Nvidia drivers to install AMD ones. I did this by deleting all of the Nvidia display drivers in safe mode using Driver Sweeper, however everytime I tried to run any kind of 3d game I would get the error message "Display driver stopped responding and has recovered", referencing the "AMD Driver" as the driver that failed. I thought there were still remnants of Nvidia display drivers clashing with the AMD ones, so I reformatted Windows 7 and installed AMD drivers from a clean install, but the problems still persist.
I checked the temperatures using Speedfan and they were all fine, the GPU idles at around 40C~ when not running anything, and only goes up to about 55C when I tested it with Dungeon Defenders in windowed mode (which froze and played for a few seconds repeatedly as soon as I ran it and got to the main menu)
I have a Novatech 600W ATX PSU which more than meets the requirements for a single HD4870 card (the box quotes 500w and above) and the Novatech PSUs are apparently reputable and are simple rebranded from another named brand of PSU, so I do not think it is a power issue.
I really am at a loss here guys, please help me out :C
I can post a DxDiag log if need be
(Nothing is overclocked)
Operating System: Windows 7 Ultimate 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.120830-0333)
Processor: Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz (4 CPUs), ~2.4GHz
Memory: 4096MB RAM DDR2
GPU: Radeon HD 4870
PSU: Novatech 600W ATX
Motherboard: ASUS Benicia (From a HP Pavilion which this computer originally was)