Bill Pytlovany, the developer of WinPatrol, has announced a "back to school" offer of $10 off on WinPatrol PLUS, which normally sells for $29.95. He says explicitly that you don't have to be a student to take advantage of the offer, which runs through the end of September. More details can be found on his blog at http://billpstudios.blogspot.com/2009/09/winpatrol-plus-back-to-school-special.html
WinPatrol is a terrific program for monitoring your computer. It will warn you of any changes made to your system (e.g., if a program adds itself to your startup menu or tries to modify your HOSTS file), and you can approve or reject the changes. You can also use WinPatrol to see and control what programs are already scheduled to start when you turn on your computer, what programs are currently running, and a lot more. WinPatrol comes in a free version, but I'd recommend taking advantage of the above offer for the PLUS version, which offers real-time detection of newly-installed programs and a huge database of easy-to-understand information about the files it detects. The developer provides very prompt and helpful responses to questions, as well as a guarantee that once you pay for the PLUS version, all upgrades are free: you never have to pay for new versions. I bought WinPatrol PLUS several years ago after reading the unanimously glowing reviews of the Neat Net Tricks Software Review Panel, and I've been delighted with it. Available for all versions of Windows from Windows 98 through Windows 7, including x64 systems.