In Outlook 2000, I get a message when sending emails:
Interface not registered

Nothing on support.microsoft.com
I have not yet tried officeupdate yet.

Please help me to figure this out.

I have seen others on the NGroups with a similar issue and no one has
answered them.
I cross-posted to get the most eyes on the problem.

--- REPLY SEPARATOR ---
(only needed because OP posted using HTML which is NOT recommended for
Usenet posts - do NOT use HTML when posting to Usenet)

Are we to guess WHICH type of mail server to which you connect?  Exchange?
POP3?  IMAP?  HTTPmail?

Did you check before posting here at the huge Microsoft support
knowledgebase site at http://support.microsoft.com?  Without the REAL error
message to use in a search, I could only search on "interface not
registered" and selected "Outlook" (no version) as the product.  One of the
matched articles was http://support.microsoft.com/kb/870707/en-us.

Sometimes it actually works in a search to NOT specify a version if a
no-version selection is available.  The reason why I ask is that I thought
this error message (or one like it because you didn't give us the full error
message) could also be caused by an Exchange account defined in Outlook that
wasn't working.

FYI:

When cross-posting the SAME message, cross-post to RELATED newsgroups.  The
Windows Update group was definitely an unrelated group.  The Office Setup
group really isn't related, either.  If you don't know if your topic is
related to a group then DO NOT post there!  Shotgunning your post across
unrelated groups is rude.  Getting "the most eyes" means you posted an
off-topic message in unrelated groups.  Maybe that is why your posts were
getting ignored.  KNOCK IT OFF!  If you don't yet have the feel for Usenet
posting, do some Google searching and lurk for awhile to see how it is done.

I changed the groups list to only include the related ones (i.e., those for
Outlook) in my reply.