Windows only: LookInMyPC generates a complete report of what's going on in a computer—from hardware to software, and everything in between. After playing around with it, this writer wouldn't start troubleshooting a PC without it. I'm not kidding. Whether you're a tech guru who knows your way around your computer better than the company that built it, or a novice just getting acquainted with your system, LookInMyPC is a free app you'll want to download and run at least once, even before you need its diagnostic help. It's like a big verbal X-Ray of your PC, detailing everything from the brand of network adapter you have to the number of user accounts on your system. Everything that a LookInMyPC report generates can already be found in your computer's accessible files if you know where to look, but this utility makes it so much easier. Just open the system inspector and tick the boxes to select all or some of the more than 40 diagnostic checks you want it to perform. Seconds later, you'll have a long report outlining every detail LookInMyPC ferreted out for you. Stash it in a drawer with your computer's owner's manual for a fast and handy reference sheet the next time you need to know what brand sound card you have or what the specs are on your processor. Read more: Lifehacker