For some odd reason, I was just playing a game, running at a fine 60 fps, when suddenly it slows to a meager 8 fps. And not just the game has been affected. My whole system has. It no longer plays audio or video files properly, instead it’s skipping alot and making static noises everytime I try and play them. I’ve tried system restoring, Defragging, Disk cleanup, Startup alterations, Registry Cleaning, and no malware, viruses, or anything like that is there, and none of it has worked. I’m at the end of my rope, here. What do I do?
For some odd reason, I was just playing a game, running at a fine 60 fps, when suddenly it slows to a meager 8 fps. And not just the game has been affected. My whole system has. It no longer plays audio or video files properly, instead it’s skipping alot and making static noises everytime I try and play them. I’ve tried system restoring, Defragging, Disk cleanup, Startup alterations, Registry Cleaning, and no malware, viruses, or anything like that is there, and none of it has worked. I’m at the end of my rope, here. What do I do?

EDIT: I’ve only had my com for 6 months, and I haven’t really pushed it all that much. It’s a Vista, with a 3.00 GB RAM, AMD Turion X2 dual-core mobile technology RM70 (2.0 GHz, 1 MB cache), and up to 1408 MB ATI Radeon HD3200 Graphics HyperMemory. Maybe this helps some more.
EDIT: Well, I have over half my memory available, about 81.5 GBs. I’ve already done a registry cleanup, and there`s only 2 programs that start at startup. Used to be 4… Anyway, the only possible thing I think there’s left to do is reinstall Windows. Programs are slower, though. Like I said, my whole system has slowed down. Even when I download something, it`s slower, and I have high-speed internet. Even moving or copying programs to different spots is WAAAAY slower than what it used to be. A while back, I do believe this happenef to me before, but only visual effevts were affected, and not the speed of the com. I think it was cause of ‘Windows Silverlight’. So, I did a system restore, and everything went back to normal. This is different, though.

I need a trustworthy registry cleaner that lets me clean the whole thing without the need to purchase the full program.

I hate those demos that scan your computer and then want you to buy the full version before they’ll clean it. Where can I get a free full version cleaner? Please include links.
I’d like to thank all of you who answered and I wish I could give you all stars. However, I can only pick one.

I’m currently experiencing a really bad virus.

First, I got a Windows Antivirus Pro, but managed to remove it and run Malwarebyte’s Anti Malware. After that, I thought it was all good, but my search results on google started redirecting to other things. Then, I got a Windows Police Pro. I removed the program files and fixed the registry so I could run programs. But there’s still something on my computer. Whenever i try to run an anti spyware or anti malware program, it halts abruptly and then I can’t open it at all. Also, my registry cleaner had the same problem. They all failed when they got to a cirtain part of the registry. AVG got through the registry without failing. I also have some suspicious processes:

msiexec.exe
mscorsvw.exe
b.exe

Also, when I was playing a game, I noticed a whole bunch of clicking sounds, as if the web browser went to another page. There was no web browser running at the time though.

Can anyone help?
Some more details:

I’ve tried SuperAntiSpyware and it won’t work. It always stops and crashes, even in safe mode.

For some reason, All my system restore points are gone.

Registry Cleaner help?

Okay, I really need some help choosing some registry cleaners. I have Maplestory, Solider Front, and Combat Arms, but I only really play MS, but my cousin often comes over and plays SF and CA. So, now my PC is all jacked up. It can be really slow, that I often have to restart the PC in order to connect to the internet. Don’t reply saying that I should uninstall it because I’m not. Are there any good Registry Cleaners that are pretty good, and is a freeware? I have CCleaner, but it doesn’t find much errors, when other "professional" cleaners can scan up to 3000 problems on my PC, but are way too pricey. Please, I need registry cleaners and defragmentors that are freeware and does pretty god job on it. Remember: I have CCleaner already, and it’s not really good.