Sudden lag when playing games?

[luso]

My custom built desktop ran all of the games that I threw at it (mostly Skyrim, Grimrock, and the Dragon Age games) flawlessly on ultra. I stopped playing games for a while because of school work, and when I started up Skyrim again, I started getting crippling lag in both ultra and high settings, forcing me down to medium. This occurs in all of the games that I used to run perfectly. Here are my specs;

Operating System: Windows 7 Professional 64-bit
Mobo: Gigabyte Z68A-D3H-B3
CPU: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz (4 CPUs), ~3.6GHz
Memory: 8192MB RAM
GPU: AMD Radeon HD 6950 w/ 2GB dedicated

I did some research on similar problems beforehand, and haven't found anything that helped me. My computer recognizes my graphics card and my monitor is plugged into the graphics card. I tried using someone else's 6950 to the same effect. I tried rolling back my drivers. (As far as I know) There are no processes running in the background that weren't there before. I've tried closing my antivirus while playing to no effect.

Anyone have any idea what can be causing this so suddenly?

EDIT: Skyrim shows two AMD Radeon HD 6900 Series options when choosing a graphics card, both options have the same amount of lag. Dunno if that's important.

 

[geekapproved]

What power supply?

Really makes no sense how that could happen unless your psu is failing.

How do you know it's not your internet that's lagging?

 

[swifty_morgan]

cookies/malware/virus'.......... clean up machine.

 

[vrumor]

Do a clean sweep of the AMD drivers and install 12.4. Also could be your power supply, what PSU do you have?

 

[swifty_morgan]

did you install the CCC ( catalyst control center ) ? if so, right click on the icon in the lower right corner and "exit" it. Then try the games.

 

[luso]

Thank you all for the replies!

@GeekApproved - Ah, forgot the PSU. I've got a Corsair Enthusiast TX750. How would I know whether or not my PSU is failing? I haven't experienced any random shutdowns or anything.

@morgan - I've run several virus scans (MSE and Malwarebytes), and they all come up empty. I can't close CCC from the taskbar, should I just go ahead and force it closed from Task Manager?

@vrumor - I'll do that and get back to you.

 

[luso]

Best answer selected by luso.

 

[luso]

Vrumor got it! Uninstalled CCC/drivers, used Driver Sweeper, reinstalled and I'm good to go. Thanks everyone!