Error opening attachments in Outlook

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.

Solution: Cleaning out the Secure Temporary Outlook Files folder.

Location of the folder:

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

Stored in OutlookSecureTempFolder registry key.

Superfetch, prefetch off (SSD use)

SSD thread if needed (highly recommended: D), disable the Prefetch and Superfetch:

Use the good old regedit:
HKEY_LOCAL_MACHINE ⇒ SYSTEM ⇒ CurrentControlSet ⇒ Control ⇒ Session Manager ⇒ Memory Management ⇒ PrefetchParameters

EnableSuperfetch = 0
EnablePrefetcher = 0