I upgraded to a 8.1 computer and installed CCleaner on it. It gave a LONG list of registry errors and I am wondering if the program has been tested/validated with 8.1????
I'm tempted to let it clean up but save the deletions to see what happens, but I would feel better if I had some input from others.
I've had w8, then 8.1, then 8.1u1 more or less as they have come out.
I've run the reg cleaner maybe 3 or 4 times on my PC since w8 with no noticeable ill effects but there-in lies the rub, reg problems can take ages to show up.
So absolutely do the offered backup before any reg clean.