I have installed Spam Bayes 1.1a6 on Windows 8 Pro and Outlook 2010. It was installed disabled for some reason. I enabled it by going to File / Options / Then selecting "Disabled Items" in the Manage drop down at the bottom of the page and clicking the "Go..." button. I selected Spam Bayes and enabled it. I then selected "COM Add-ins" from the Manage drop down and clicked "Go..." I scrolled down to find SpamBayes and checked the check box and clicked OK to back to Outlook. Spam Bayes showed up in Add-Ins tab and seems to work so far.