Outlook email attachment error message: "file cannot be created"

Cause
The temporaryinternetfiles folder is stored on the server when you have no permissions.

Solution
If you modify the Registry correctly, you can use the registry editor or other methods to warn that a serious problem may occur. These problems may require you to reinstall the operating system. Microsoft cannot solve these problems. You are at your own risk to modify the registry. To resolve this issue, force outlook to use temporary files for specific folders. Modify the Windows registry as follows:
Microsoft Outlook 2000
If you are using Outlook 2000, perform the following steps: 1. Start the Registry Editor.
2. Locate and click the following registry key:
HKEY_CURRENT_USER \ Software \ Microsoft \ Office \ 9.0 \ Outlook \ SECURITY \ outlooksecuretempfolder

Note that you may have to manually create this registry key if it is not on the system.

If outlook is installed on the terminal server, use the following registry key:
HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows NT \ CurrentVersion \ Terminal Server \ install \ Software \ Microsoft \ Office \ 9.0 \ Outlook \ SECURITY \ outlooksecuretempfolder
3. In the "edit" menu, click Modify and add the following registry values:
Value Data: folder, path and name to be used
4. Exit the Registry Editor.

Microsoft Outlook 2003
If you are using Outlook 2003, perform the following steps: 1. Click Local, and then double-click drive C.
2. On the File menu, new, and folder.
3. Name the folder temp.
4. Click OK and start, type regedit, and run.
5. Locate and click the following registry key:
HKEY_CURRENT_USER \ Software \ Microsoft \ Office \ 11.0 \ Outlook \ SECURITY \
6. In the right pane, double-click outlooksecuretempfolder.
7. In the value data field, type C: \ temp \, and click OK.
8. Exit the Registry Editor.
9. restart the computer ..