I downloaded the free version and immediately ran it. It identified several POPs and removed them. So far no problem. Today I got a message saying that my free version expired tomorrow, and I would need to purchase the upgrade. I was undecided but thought I'd run the scan again in case I didn't purchase the upgrade. Before I could even run the scan, the program gave me a message that I had a malware file in the PaintShop Pro program that I have been using for years. Malwarebytes did not even give me the choice of whether to remove the identified file; the file was simply deleted, and I had to reinstall PaintShop Pro to get it to run again. For a freeware program to cause a problem like this is no way to sell an upgrade!