maam

Would it help if I went back to the pro version that I purchased Dec 29, 2017 and downloaded it then tried my License to register? I think I saw a list of the versions somewhere.

I use the pro version on my W7. I purchased it 12/9/2017. When I was notified of new version (5.42.6499) I updated and the program came up as unregistered. My license was invalid. I have re-installed numerous times. After reading several posts I downloaded and installed 5.41.6446 - I still get the message that my license is not valid. Please help!

I am having the same problem of invalid License - I do not understand when it was suggested I download from Piriform - the only thing I see is buying CCleaner pro. I have already purchased it - the license is not working. Is there a support at Piriform? Tech at CCleaner told me to delete Ccleaner from my W7 then gave me a link to redownload (which I have done several times) and re-enter my name and License code. Still get "invalid". Please help.

I, too, am having this same problem - I am using W 10. I tried deleting the program and re-installing four times - same error message each time. I will try deleting once more and then shut down and re-boot and see what happens. I am new here - hope I did this right.