The problem started after no changes that the owners of the PC now about, as I said they are old.
No registry clean up tools were used, and as I stated a new install of OE did not help, even after following anothers advice of renaming the reg keys
HKEY_USERS\DEFAULT\Software\Microsoft\Outlook Express
HKEY_USERS\DEFAULT\Software\Microsoft\WAB
HKEY_LOCAL_MACHINE\Software\Microsoft\WAB
even using the orig version of OE, v4, it still had same problem - install OE6 from a PC magazine disk - no change.
thanks for the explanation - already knew about the GUID, but it helps to have it clarified.
any help at this point is very appreciated