Penzap

From Penzap:

These days spyware, adware and other malicious software programs are everywhere, and it seems almost impossible to stop them. You can be infected just by visiting a website, or by installing a popular software title. Once you are infected with even one of these malicious programs they can download and install even more. In fact, the people that produce spyware and adware pay good money to software developers to distribute their malicious programs. The more spyware they can get installed on your computer, the more money they make. Our software goes above and beyond your typical spyware removal software and actively monitors which programs are running on your computer. If it sees a spyware or adware program trying to start, it will stop it dead in it's tracks.

Version 3.2 includes 24 hour protection.