Completely remove Outlook up and start afresh

To ensure you get a complete reset, uninstall it, delete the data files and reinstall.

Here are instructions to help if you need them; Install or remove individual Office programs and components

Re-installing is waste of time...

just go to control panel>>mail(32bit)>>show profiles>delete all profiles here.

then open the outlook, you will be opening an fresh account.

NOTE:1.before deleting don't forget to take mail backup.

NOTE:2. On windows 8, 8.1 and 10 you can use windows + x and select Control Panel.

Shockingly, you can delete all your profiles and even uninstall, reboot, and reinstall Outlook and still have nasty issues that linger.

Some stuff that will not be reset includes....

• Any VBA scrips
• Any ribbon bar customizations
• The database of which emails have already been downloaded via POP3

...and lots of other stuff that can haunt you.

To completely reset Outlook, you must....

1. Uninstall the Outlook application
2. Delete all the profiles
3. Delete the tree under the registry key [HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office] (or you can go in and only delete the sub-trees for your Outlook version if you want to keep state for other Office applications)
4. Delete (or rename to a .bak) the folder C:\Users\[your user name]\AppData\Local\Microsoft\Office or %localappdata%\Microsoft\Office
5. Delete (or rename to a .bak) the folder C:\Users\[your user name]\AppData\Roaming\Microsoft\Office or %appdata%\Microsoft\Office
6. Delete (or just don't use) the previous PST file.

I only know all this because I had a nasty problem where Outlook started downloading messages over POP3 and then deleting them. Deleting all profiles, PST files, and uninstalling/reinstalling did not solve the problem. Only after following all the above steps did the problem go away. I still can't figure out exactly where the POP3 messages database is actually stored.

In the recent versions of Outlook the Mail option in the Control Panel has been removed. Even so, you can use the /profiles switch for outlook.exe to open the Outlook Mail Profiles window even if Outlook accounts are hosed.

Run outlook.exe /profiles from the start menu to open the Profile selection window. Now click options then delete. If warned about data loss you'll need to confirm removal. Repeat for any other profiles.

If you want to remove the PST, OST & NK2 files (effectively all your data so caveat emptor) you can delete them from the folders:

1. %LOCALAPPDATA%\Microsoft\Outlook
2. %USERPROFILE%\Documents\Outlook Files

Now re-open Outlook and you'll be prompted to create a new profile and add an email address to it.

The entire process can be completed in under 5 minutes, but you'll then need to re-download all your email so expect that to take some time for people with large mail archives.