check this tip. worked for here
http://mobeer.blogspot.com/2009/01/excel-2007-cannot-empty-clipboard.html:
This might save somebody some time and headaches if google picks it
up. I was getting a 'Cannot empty the Clipboard' error every time I
moved cells around in Excel - eventually I mucked around with the
settings and made it go away. Here's how; In the excel main menu
(glass globe w/logo), click Excel options, then Advanced, then turn
off 'Show paste options buttons'
How exciting was this as my first post of the year?
Update: I still haven't found a permanent solution but I found another
thing that seems to help. In Excel 2007, from the "home" tab, the
first thing on the left is the clipboard tool panel. Expand the panel
to view the clipboard and in the clipboard you might find "cannot
empty clipboard" as an entry. Empty the clipboard, keep the panel open
for a second or two while you do a few cut and pastes/drags etc. and
then the bogey seems to go away.
I call this the cable dance because back in the day I had a printer
that only worked if you unplugged the cable, shook it out and plugged
it back in.
