Right now, I'm getting it in Excel 2007, but I've gotten the same error in pretty much every version of Excel I've used since 97. The only discernable similarity is that happens on my office PC. It's never bothered me on my home PC.
In Excel 2003, I was able to mess around in the clipboard options until it went away. In 2007, though, the options seem to be seriously limited and generally useless. Google wasn't much help, either.
Are you running Skype? This has been the best solution I have found to get rid of the "cannot empty the clipboard error" in Excel 2007 & 2010. Delete the Skype add-on in IE and/or Firefox and good-bye annoying error!
In reply to rjacobs7 post on February 28, 2011
Cannot clear clipboard error - Windows 7, Excel 2010 - This error occurs nearly every time a drag and drop of cell contents is attempted. I've had this same error over the past 10 years on older computers and older versions of Windows and Office. It has now reoccurred with a new laptop running Windows 7 64 bit and Office 2010. The issue can be replicated only if a browser - IE or Firefox - is open at the same time that Excel is open. Having Word and/or Outlook open at the same time will not cause the problem to occur unless a browser is also open. This error is extremely irritating and no solutions from Microsoft or other posts on this issue resolve it.
I have a solution - at least for me! Delete the Skype add-in in IE and Firefox and the "cannot clear clipboard" error after a drag and drop goes away when IE and/or Firefox are running. Apparently some sort of memory-management issue with Skype, Office and the browsers.
I copied a picture (instead of text) that I had in my excel 2007 file and that solved the problem for me. The picture copied to the (then empty) clipboard. I could then copy cells normally even after clearing the clipboard of the picture. I think a graph object should also do the trick.
Try http://support.microsoft.com/kb/207438 which will work for 2007 if you follow v12.0 in the registry.
I have seen various answers which say when I uninstalled this or that it worked. I think that the uninstall is probably just sorting out an issue in the registry, rather it being an issue with the particular application that is being uninstalled.
I have also seen cases of people saying kill the RDP task but I don't have that and I still have the error.
I have seen cases of people saying clear the clipboard in Excel, but that doesn't work for me - nor does changing the settings in the Clipboard.
I believe that the issue is that an application has a lock on the clipboard and that application is not releasing it. The clipboard is a shared resource, so that implies that each application has to get a lock on it before changing it and then release the lock once it has completed the change, however, it looks like sometimes the lock is not released.
I found that the following cured it. Close down all MS applications including IE and Outlook. Check Task Manager processes to make sure that they are all gone.
Then restart the application where you had the Copy and Paste issue and it will probably then work.
Regards
Paul Simon