Hi.
I recently took a class called OS TROUBLESHOOTING (at Sinclair Community College, in Dayton OH), and that does
NOT make me an expert at troubleshooting computers. So feel free to take this post with a grain of salt.
However, just FYI - the gentleman who taught the class has been doing it for ages, and he recommended a couple different tools.
One of them was Glary Utilities -
http://www.glarysoft.com/
and another one was called CCleaner -
http://www.piriform.com/CCLEANER
But that doesn't mean there is anything wrong with the one you are currently using. There are a LOT of them out there. I'm simply passing along info I got from a guy who teaches a class about operating systems.
Another thing to note is unlike Anti-Virus tools, you can run more than one of these (one right after the other) without causing conflicts. I use both of the ones he recommended.
Another site he mentioned as 'very cool', was NiNite -
http://ninite.com/
Check out the highlights listed there. You can get some neat programs all at once, and they remove all those bloatware things like extra unnecessary toolbars and search engines and crap that free programs are always trying to get you to accept during their install process.
I also use the free version of AVG, and the same professor said he thought AVG was just fine (If I recall correctly, he said he uses a paid AV program himself).
I also have my computers set to auto-install all important Windows updates once a week ( I just set it to something like Wed night 3am, so it's usually while I'm sleeping).
Just FYI - combing all of the above, and I haven't had any kind of computer malware issues in a very, very long time. I don't even recall the specifics of the last time I had a problem, because it's been that long. So regardless of what anyone may think of the information in my post, I can honestly say (why would I say anything dishonestly

) that it's working for me.
Another thing I can suggest about a slow computer is something I was surprised to learn a lot of folks aren't aware of - is to make sure your hard drive is nowhere near being close to full. Make sure it has plenty of empty space. I forget the exact numbers they said, but don't even get close. For example, if your hard drive is more than 3/4 full, I'd start getting rid of stuff. I don't let mine get more than half full.
It's impossible to read your post and immediately point to the actual problem. There are a lot of things that can slow down a computer. Google your butt off looking for lots of different suggestions. But one possibility to mention right away is that a dying hard drive can cause slow downs. If I was you, I'd start making important backups right away, just in case. If you have anything you simply cannot live without, back it up
right now.
Running anti-virus programs in safe mode, removing covers off your computer and doing some serious dusting (heat is bad), make sure your fans are all working, do all your backups and then run a restore disc... there are lots and lots of things you can do.
Good luck to you sir.