Just a guess...

I'm guessing that there's a workbook that tries to close an addin that it
needed. But if that addin has been closed or moved or removed, then maybe this
message will show up.

I'd try to do some detective work--is it closing a single workbook that causes
the trouble--or all workbooks?

I'd look to see what workbooks were closing when the message popped up.

Even these say they're for finding startup errors, you can use them in your
detective work:

Chip Pearson has some notes on how to diagnose startup errors:
http://www.cpearson.com/excel/StartupErrors.aspx

And Jan Karel Pieterse has more notes:
http://www.jkp-ads.com/Articles/StartupProblems.asp

jhicsupt wrote:

I keep getting a message that "Cannot find "c:\Program
Files\Microsoftoffice\Office11\Library\....., which has been assigned to run
each time [filename.xls] is closed. Continuing could cause errors. Cancel
closing [filename.xls]?

How do I remove this message?

Thanks in advance.

--

Dave Peterson