Use this: http://www.pcdecrapifier.com

Why? Because the computer you just bought at the store is already bogged down by a bunch of useless crap totally useless crap before you ever even get a chance to turn it on and make the situation even worse yourself. (That's a joke. I know not everybody has commited their lives to making their computers bad places to be.) Anyway, this will strip out all the things you'll never even know you had, and wouldn't dream of wasting your time getting pissed at in the first place even if you did.

Seriously, for a lot of folks this will be like a computing rebirth. Don't think your brand new big-buck PC is performing like its specs say it should? You're probably right. Decrapify it.