Just purchased Grime Fighter verified license and after the reboot got the message in the subject along with the following:
Your windows settings have some data we don’t recognize. to play it safe, we can’t run on this PC.
Any ideas what to fix or do I need to request a refund?
What os/sp?
Windows 7, SP 1
You may need to request refund.
I read elsewhere that Davidek (Avast Team) has said this message unfortunately results in not being able to run Grimefighter on your OS configuration.
I’ll see if I can draw some attention.
Please keep in mind this is the weekend now and Monday would probably be the earliest for reply/confirmation. 
Hi bolandorders,
Please open a ticket with our support team to get a refund. Because GrimeFighter looks into all the deep corners of your PC and tries to clean all the junk it takes a very cautious approach to doing that if it sees anything in the registry or otherwise that might somehow cause issues with your PC after it runs.
Because of that, you have received this message. It isn’t necessarily your OS but more registry or disk configuration.
We should be releasing a new build of the product in mid-Feb that checks this status before presenting the initial offer to users. That way, we can determine if we can run the product on your PC or not before you purchase it.
Best regards,
Davidek