Recently (About a month) my computer has been really sluggish, taking longer and longer to start up, I'm also getting low FPS counts when they used to be and should be high, programs are taking ages to open, and occasionally freeze. I've done so many virus scans (different programs) and they have all found nothing. It's gotten to the point today where I can't even run Starcraft 2 on low settings without the fps dropping and the game freezing, where a month ago it ran fine on Extreme (Never below 60fps).

CPU: [Intel] I7-2600k [Overclocked to 4.4Ghz]
GPU: [NVIDIA] Galaxy GeForce GTX 570
RAM: 4GB Corsair Dominator DDR3
Motherboard: Asus P67 Sabretooth B3 Rev
Power Supply: Silverstone Strider Plus 750w [Full modular]
Hard Disk Drive(s): 1 TB HDD, pretty sure it's a Samsung Spinpoint F3

What am I dealing with here? What's the issue? More importantly, what is the solution?
Thanks.

ssd missing and unstable clocks? gpu dieing could be a number of things reset all ur clocks and try then?

so the first thing you think is the problem the fact he has no SSD? you ******* insane or just dumb?

format and start over

^this, try undoing overclocking then do a disk cleanup/Cclean/registry clean first tho, check ur system temps too

I'll back up all my data, and format it tomorrow or the next day, I'll post how it goes then.

Anyone have any other ideas what it could be though?

system restore and if u really want do a fresh install

Might be getting to the end of your hard drive, they run slower as they get fuller. Maybe do a mass uninstall of random programs you dont need?

I gather you've got aftermarket cooling? Seeing as how you've overclocked your CPU. If not it could be your CPU overheating.

Water cooled.

Doesn't go over 30.

Unsure then :/

could be porn?

No they don't wow.

Run hijackthis and pastebin the log to here
use ccleaner to clean up all shit on your pc. Chances are you've got a virus.

make sure you've got SMART enabled in your bios and run this - http://www.seagate.com/ww/v/index.jsp?locale=en-US&name=SeaTools&vgnextoid=720bd20cacdec010VgnVCM100000dd04090aRCRD

run DEBAN its a wiping tool that completely wipes your hard beyond recovery also used by the department of defence and run a few passes and reinstall windows for a fresh new start and stay away from the rubbish such as illegal downloads, porn,torrents etc

I would clear cmos and reset all clocks/volts ram timming to defaults if i was you before doing anything

what would he achieve by doing that?