Try this site…
Its affliated with PCWorld.com. It’s free but you can register if you wish. It tells you a lot about your system.
I love PC Pitstop. I run my computer through the diagnostic once a month. It has made a big difference for me. I haven’t had any trouble with my system at all since I started it.
Nice site, even has free web-based virus checking. Not as comprehensive as the ones you pay for, but worth the time likely.