I use the Turtle Beach x12... It has held together for years, has a great microphone, I've sat on it before on accident and it didn't break, and I bought it for about $20 USD.
Well...
-Get a program called CCleaner - It cleans out old DLLs and unused files, but won't touch anything you have done unless you tell it to.
-Do a disk defragment.
-Clean out your downloads and recycle bin.
That's about the few really basic ways to make it run faster.