I suppose I can try. I did create a Restore Point just before I started the update to Windows 8.1, but I assumed that nothing was done yet to restore from, because Windows 8.1 won’t install if there are any programs still installed that are incompatible. But I will try restoring to that point now, run both of the Avast cleaning programs, and then try the 8.1 update again, and I will let you know how it went. It’s worth a try.