A few useful (and free!) tools to keep you up and running.

CCleaner is a powerful, free computer maintenance tool that will keep your PC from the annoying buildup of crud that eventually slows the performance of all computers to unacceptable levels. With it's simple, user-friendly interface, it makes maintenance as painless as possible, and as a side note, I use this almost daily and swear by it! Download CCleaner here

Advanced Windows Care: Quite similar in execution to CCleaner, this utility delves even further into regular maintenance tasks like simple defragmentation, and scans for malware. I use this in conjunction with CCleaner and it is quite effective. Download it here:

Revo Uninstaller is an incredible tool I stumbled across that, in essence, does exactly what the title implies: it removes stuff. It also prevents the data bottleneck that occurs every time you start your computer and multiple programs are scrambling to start at the same time. Do you have enough time to brew a pot of coffee before you are actually able to get online? Now, you don't need to waste time booting up. Revo Uninstaller Free

While there are many different anti-virus solutions out there that don't require a fee, my favorite, especially since it is so unobtrusive, and doesn't over-burden older systems is AVG Anti-virus. What you get is basically the same level of protection that Norton or Macafee would provide, without the subscription service hassle. AVG Free Anti-virus