1. Delete all folder/keys under this registry hive.
2. Delete all Outlook cache file under this directory.
> Go to this location by pasting it on Windows RUN
|%userprofile%\AppData \Local \Microsoft\Outlook|
> Rename the whole Outlook Folder
**If account is on IMAP set up check first if you have contacts and
calendars saved locally on the account, if you have, refrain from doing this as this process will delete local cache.
3. Delete all profile in Mail (Control Panel)
4. Run quick repair on user’s Office suite and restart the machine
5. Setup a new outlook profile.
6. Observe for any issue encounter.
Should you have one, click here