Unable to send e-mails using Office Outlook or Outlook Express due to 'interface not registered' error

Cause of this behavior: If the Ole32.dll file that is located in the %Windir%\System32 folder is not registered correctly in the registry.

To resolve this problem, register the Ole32.dll file. To do this, follow these steps:

Click Start menu
Click on Run command
Type the following command in the Open box, and then click OK: Regsvr32.exe %Windir%\System32\Ole32.dll
In the RegSvr32 dialog box, click OK.

In general the location of the program must be :c:\windows\system32\ole32.dll

If necessary, replace "c:\windows\system32" with the actual path to the ole32.dll file on your computer. You only have to run this command once (not every time you start the computer). Exit and restart Windows.

For more information you may visit the following article:

Article: You receive the “Interface not registered” error message when you try to send or to save an e-mail message to the Drafts folder in Outlook 2002

http://support.microsoft.com/kb/870707

Note: The above steps works with most of the Office Outlook and Outlook Express versions.