Sometimes removing or disabling Windows (or MSN) Messenger causes Outlook Express to open slowly. This will shown by an entry in the system error log: The server {FB7199AB-79BF-11D2-8D94-0000F875C541} did not register with DCOM within the required timeout.

To fix this, run Regedit (Start > Run) and navigate to this key:

HKEY_CLASSES_ROOT
    \CLSID
        \{FB7199AB-79BF-11d2-8D94-0000F875C541}
            \InProcServer32

In the right-hand pane, double-click on the (Default) value and delete whatever is entered there, leaving it blank. Click OK. Now perform exactly the same step with the key directly underneath, namely

HKEY_CLASSES_ROOT
    \CLSID
        \{FB7199AB-79BF-11d2-8D94-0000F875C541}
            \LocalServer32

Once both (Default) values are empty, Outlook Express will open normally.

[Source: http://insideoe.tomsterdam.com/]