Are you sure it's really an addin? It should have been saved as an addin,
not simply the extension renamed.
Select the file in project explorer and change the IsAddin property to True.
Save from the VBE.

Regards,
Peter T

"Tony Logan" wrote in message
...
I have an add-in that runs when a user either first starts Excel or opens
a
worksheet. The add-in checks any opened worksheet for several things
(fonts,
tagged data, etc.).

The add-in is in the XLStart folder (running Windows XP, SP2, so the path
to
the add in is C:\Program Files\Microsoft Office\OFFICE11\XLSTART).

When I open Excel, the add-in is visible and appears like any other
worksheet (except that it's named with an xla extension). The add-in is
set
as read-only, so there's no real danger that users can change it, but I'd
like to know if there's a way to either keep the add-in from appearing
(best-case scenario), or failing that, at least minimize the add-in.

Thank you.