Error Meesage when you open attachment from outlook

Just like screenshot below :

Solutions :

If you are using Outlook 2010, follow these steps:

1. Click My Computer, and then double-click drive C.
2. On the File menu, click New, and then click Folder.
3. Name the folder temp0.
4. Click Start, click Run, type regedit, and then click OK.
5. Locate and then click the following registry key:
   HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Security\
6. In the right pane, double-click OutlookSecureTempFolder.
7. In the Value Data field, type C:\temp0\ and then click OK.
8. Exit Registry Editor.
9. Restart the computer.

Works smoothly for me!