1.    Hold the Windows Key, then press “R” to bring up the Run dialog box.

2.    Type “Regedit“, then press “Enter“

3.    Click “Edit” > “Find” and type “OutlookSecureTempFolder“

4.    When regedit has found the entry, it will tell you where your Outlook temporary files are stored. It will look similar to one of the following:

C:\Users\username\AppData\Local\Microsoft\Windows\INetCache\ Content.Outlook\randomnumber\

C:\Documents and Settings\username\Local Settings\Temporary Internet Files\OLKrandomnumber

5.    Bring up the File Explorer, then navigate to the location in the registry key.

1. Delete all of the files in this folder.