1. Boost the memory

Everybody knows adding more memory can boost a computer's performance. And even a newbie can figure out how to snap memory modules onto a computer's motherboard. But which modules? Memory comes in many different versions, and you must pick the right one for your machine.

Crucial.com, a leading memory chip vendor, has a bit of free software that will identify the type of memory in pretty much any PC. Run the Crucial System Scanner and in seconds, you'll know what kind of memory you have, and how much of it. If it's less than a couple of gigabytes, it makes sense to add more - especially since memory is fairly inexpensive. A gigabyte's worth sells for $30 to $40.