RobRay

Hi Hazlel, I was always a bit reluctant to uninstall in case just the licence key was insufficient to return everything. I've done it now and activating with the old licence key returned everything including the correct funding. More importantly CCleaner is now back to normal and opens up quickly. Still a bit of a mystery as to how it got corrupted. Thanks very much for your help. Regards Robert

Thanks Hazel, I'll give that a try.

One thing I should have perhaps pointed out is that I have purchased 2 copies of CCleaner Pro. One on my main PC and the other on my backup PC. The backup is an old Zoostorm PC, replaced Win 7 by Win 10. The CCleaner version and the Windows updates are the same on both PCs. However my backup PC has no problem with opening CCleaner in about 1 sec. On my main PC, once CCleaner is opened, it appears to be working as normal.

Thanks Hazelnut, Details attached as requested. Doesn't look particularly informative to me except having a double entry for CCleaner.

Perhaps there's a clue to the slow opening in the attached screen shot of the Task Manager. Looks as though some pretty heavy pre-processing is going on before CCleaner displays. No idea what this means.

Thanks Andavari, I use Malwarebytes and Microsoft Defender is turned off. Presumably therefore Cloud Protection is not active.

Thanks hazelnut, yes that was one of the things I tried but made no difference.

Thanks nukecad. I have CCleaner Pro 5.91.. and have already installed KB5011543. Still very slow for CCleaner to open, approx 20 sec. I tried uninstalling KB5011543, made no difference and re-installed, still no difference. Must be something else on my PC. (Win 10 64b).

CCleaner has become slow to open ? Using latest update for CCleaner Professional.

I have CCleaner Professional running on Windows 10. I have never installed Thunderbird and it does not show in Windosw apps list. Why is it present in CCleaners app list ?