I have owned my MSI HD4850 for a while now since it was released back almost a year and a half ago. I use to run it overclocked at from 625 to 725 core and the ram from 993 to 1150. About 9 months back when I still ran XP it would crash all the time. I found out that as soon as the catalyst control center started it would crash and I would get weird colors and lines on my screen.
I went into safe mode and disabled it through MS config so it wouldnt start up and crash instantly. Then I reinstalled the drivers so I could use it again.
However I could not change the clock rate. If I moved it 5 mhz lower or 5 mhz higher it would crash and I would have to do the same process.
Fast forward a few months onto win 7 RC 7100 and it would still do it. I tried changing clocks with rivatuner and other programs but it wouldn't work either. Now I am on Windows 7 Pro and it still does it.
I really want to change my clocks. I purchased BFBC2 and want to clock it back up. I figured that at my average frame rate of 30 if I clocked the core up just to 725 it should buy me 4 more fps. What can be wrong? It runs flawlessly at stock clocks. Changing it by only a megahert or even setting a new voltage to run at through any program causes it to crash windows. I have tried everything except a reflash. That is the only thing left and I am gonna try it now.
Also a more serious problem that has really been irritating me. Anti Aliasing does not work in ANY game. BF2, BFBC2, Team Fortress, Left for Dead 1 and 2, Bioshock 2, Mass effect 2 are all games I have tried and Anti Aliasing does not run on ANY of them. I recently totally redid the drivers. Removed them all and used driver sweeper. But no luck.
I haven't used my computer to game for well over a month until bioshock and mass effect game out. Those are both unreal engines and I just kinda figured there was no anti aliasing. And before that I played through borderlands which isn't an AA game. However every other game on that list once had AA. So I don't know when this stopped working. Coulda been sometime before the holidays I have no idea.
I have noticed that it crashed when going from 3d mode to 2d mode or vice versa when overclocked. I am trying to disable CCC powerplay but can't figure it out yet.
I have overclocked through the bios and set it to run at overclocked settings 24/7 even in 2d mode. This works flawlessly until I open CCC which implements it's own powerplay settings causing it to crash as it takes my clocks down from 700 and 1100 to 500 and 750 respectively. This is what's causing it to crash. Without CCC it is fine.
EDIT: I have givin up on overclocking this damn thing. CCC and it's powerplay is just screwing everything up. I have managed to set it to run at 625mhz at all times but if i overclock it to 700 CCC will try and take it down to 625 again as soon as load decreases; causing me to bluescreen or shutdown.
Try it first on another PC with a clean installation of the latest drivers and see if you have the same symptoms there. If so, then your card has a problem and you will need to replace it. Otherwise something else is wrong with your system (software or hardware).
The only way to pinpoint your problem is by installing the VGA on another computer with a clean install of drivers.