My computer seems to run at around 5 FPS in all games.
So, to keep it short, my computer has been lagging in every single game for a couple of days now. I have scanned it multiple times with malwarebytes anti malware (which found nothing), disassembled, cleaned, and put the entire PC back together, and have tried it on about 15 different games (ranging from Half Life, to Minecraft, to ARMA 2/BF3) and my frame rate hovers around 5. It started a couple of days ago, when I went to launch DayZ/ARMA 2. I didn't think anything about it, so I just rebooted and tried again. This didn't fix the problem, and I also noticed that Youtube videos will stop playing after about 10 seconds (although other videos - such as Netflix - works fine). I swapped out the graphics card with another one just to be sure, and the problem continued. I'll post my specs at the bottom of this post.
So, if anybody has absolutely any idea what is going on, please post; even if you are just guessing. Nothing has recently been installed on my computer, and it runs just fine when I'm not playing a game. All of my drivers are up to date.
i3 540 @ 3.07ghz (OC 4.4ghz)
EVGA GeForce 560 Ti (Fermi) 1GB (Also tried with a GTX 580 and a GTX 670, the problem continued)
4GB Corsair Vengeance DDR3-2000
Windows 7 64-bit
ASUS P7P55 LX
If you need any more information, just let me know.