I have two instances or two excel workbooks open, the first workbook have data that I copied and pasted into Notepad ++, to get rid of all the formatting and pretty colors from excel, then I copy all the regular text from Notepad++ to paste it into the second empty workbook in excel, but instead it pastes the last data copied from the first workbook, ignoring what was copied from Notepad ++.  To accomplish what I want, I have to close the first instance of excel then copy the data from Notepad ++ and paste it into the second empty workbook instance of excel. Is anybody else having this problem?, it seems like Excel takes control of the clipboard and don't let any other application copy data to it.

Hi,

Based on my test, I did not meet the issue whenever the two workbooks are in the same instance or not.

So check to see whether you have Skype installed in the computer.
As far as I know, if you have Skype installed in your computer, the clipboard will be influenced.
Refer to the link:
http://support.microsoft.com/kb/2697462
And this issue has been resolved in an update version.
http://www.skype.com/intl/en-us/get-skype/on-your-computer/click-to-call/windows/

I have a similar problem. Sometimes when I copy/paste from one workbook to another, the pasted result is not what I just copied.   Skype is not to blame here, it is not installed on my computer.