Error opening attachments / Cleaning out the Temporary Outlook Files folder

When opening an attachment directly from within Outlook you could get an error message saying that it can’t create the file and to that you need check the permissions on the folder you want to save it in.

In most cases the permissions on the folder isn’t the issue but the fact that the folder is “full”. When you open an attachment directly from within Outlook it will first save a copy to a subfolder of the Temporary Internet Files folder.

Cleaning out the folder will solve the issue.


Outlook Secure Temp folder

Unfortunately this is easier said than done. The subfolder name Outlook creates (on installation of Outlook) in the Temporary Internet Files folder is quite random.

In Outlook 2003 and previous, the name starts with OLK and is followed by up to 4 random numbers or letters. In Outlook 2007, 2010 and 2013, this folder is called Content. Outlook and then has a subfolder which is named with with 8 random numbers and letters.

In addition, by default, you cannot simply browse to the folder to clean it out. Getting to the Temporary Outlook Folder can still be accomplished in 2 easy steps though.

Step 1: Locate the folder
The folder location is stored in the registry in the following key;

Outlook 97 HKEY_CURRENT_USER\Software\Microsoft\Office\8.0\Outlook\Security
Outlook 98 HKEY_CURRENT_USER\Software\Microsoft\Office\8.5\Outlook\Security
Outlook 2000 HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Outlook\Security
Outlook 2002/XP HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Security
Outlook 2003 HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Security
Outlook 2007 HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Security
Outlook 2010 HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Security
Outlook 2013 HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Security

Step 2: Get to the folder

  1. Open the OutlookSecureTempFolder registry key from the location provided in Step 1.
  2. Copy the path from the key.
  3. Open Explorer
  4. Paste the address in the Address Bar and press Enter

Use OutlookTools or OutlookTempCleaner

Still not easy enough or just don’t want to go in the Registry to find the folder location? I’ve created two free tools which can do the trick as well.

OutlookTools offers besides locating, opening and cleaning up the SecureTempFolder also quite a lot of additional features to troubleshoot and tweak Outlook.

OutlookTempCleaner focuses only on dealing with the SecureTempFolder and can also be used in (corporate) login and logoff scripts to clean up the folder without any end-user interaction.

OutlookTempCleaner
OutlookTempCleaner can detect and empty Outlook’s Secure Temp folder automatically for you.