Sending a (Office) document to Outlook fails with "MAPI failure"

The error usually shows as: MAPI failure: "Unspecified error"

I have experienced this when trying to attach a word 2003 document to an Outlook 2007 email.

Solution? It's a weird one!

Close MS Outlook/Word apps. down and start Outlook Express. Go thtough the setup process (You do NOT need to configure an actual email account in order to make it work.) and complete it. Close Outlook Express down and retry to attach that doc again.

Running the below and registering the DLL might fix it as well, so I heard ;-)

regsvr32 C:\WINDOWS\SYSTEM32\OLE32.DLL