Once installed, MacKeeper runs fine until you restart your computer. Then the anti-virus doesn't work any more. On further investigation the anti-virus component in user/lib/ has hung and won't quit or Force Quit and can't be trashed as it just keeps running. In order to get anti-virus working again the entire application has to be re-installed every time you want to do a restart. Annoying to say the least. Several messages to tech support resulted in no replies.

I don't know what they claim they're winning awards for but it's not for customer service or an application that works.

I uninstalled MacKeeper and put ClamXav back. ClamXav is free and works flawlessly. Don't waste your money.