There’s a FREE version:
http://download.cnet.com/Malwarebytes-Anti-Malware-Free/3000-8022_4-10804572.html
The ‘trial’ version is 14 days, and they nag you to death about ‘upgrading’. Stay away from it. Other people I know who paid for it had a bad download, and couldn’t use the paid program. If you’ve got it on your system already, go to Control Panel (Programs & Features) and uninstall it, then restart.
Be careful on the ‘agreement’ screens. They pre-check a lot of boxes, so uncheck all and check what terms you want. It’s a great program, and if they’d quit trying to be so darned slick and sneaky, I’d probably buy a copy.
It is odd, I had paid for it but it was saying I had a trial version and it expired. Then it had an update link, which I did. It the installed itself again and I guess it picked up the key that showed I had paid because I have the paid for version back. Okay.