After running CCleaner v5.77.8521, I can not start Outlook anymore

[MMP]

Hallo to the CCleaner Team,

I can not start Outlook 2016 under Windows 7 Prof. SP1 anymore. An error window pops up telling my "The version of this file is not compatible with the version of Windows you're running". I did try the µSoft suggestet compatibility adjustments/tries on outlook.exe but this did not cure the problem.

I did an Custom Clean and Registry clean minutes before and thus shut down all my browsers (Firefox and Crome) as well as Outlook.

Before doing a reinstall, dao you have any quick bug fix on this subject?

Kind regards Manfred

[nukecad]

It sounds like you may have deleted a registry entry that Outlook 2016 needed.

Did you make a backup of the changes before cleaning the registry when CCleaner asked  you?

If you did make the backup then in your 'Documents' folder there will be a file called something like 'cc_20210317_120330.reg'
(The numbers are the date and time when you made the backup).

To restore the backup right-click on that file and select 'Merge', that should put back the registry entries that you deleted.

PS. As Windows 7 is now end-of-life it is no longer supported by Microsoft and I would be very, very, careful if using the Registry Cleaner.
You may remove a registry entry  that you are unable to get back from either Microsoft or the developer of the affected app.
(Now that it's EoL you will find you will have more problems with Windows 7 as time goes on).
You may be better leaving registry cleaning alone in future.

PPS. Are you aware that you can still upgrade Windows 7 (or Windows 8.1) to Windows 10 for FREE ? (As long as your computer hardware is compatible with Win 10).
Yes, the free upgrade to Win 10 is still working in 2021, Microsoft have just stopped telling people about it.
Microsoft don't shout about it anymore because they'd rather sell you a new Windows 10, (and it would upset computer manufacturers who want to sell you a new computer), but you can still do the upgrade easily for free.
https://www.zdnet.com/article/heres-how-you-can-still-get-a-free-windows-10-upgrade/