I cannot do Copy and Paste or Paste Special between Excel Workbooks

We have a number of Excel users in our office who cannot copy and paste between Excel workbooks. They can copy and paste between worksheets. When you highlight the section to copy and then go to the new workbook both the paste and paste special are "grayed out". This is true whether you right-click the mouse, go to the edit menu, or use control keys. This occurs with any data type and the most simple workbooks. I have seen some suggestions here but none have worked for this particular problem. I have reset the menus and renamed the .xlb files and neither helps. You can open the clipboard and the paste will work, but there is no paste special option. Any help would be greatly appreciated. Thanks!

Do you have the same problem when you open excel in Safe mode. Try opening Excel without any Add-ins or hidden workbook. Click on Start > Run and type C:\Program Files\Microsoft Office\Office\Excel.exe /Safe. Or Excel.exe /Safe

I just tried what you suggested and I do not have the same problems. What should I check next. I really appreciate your time.

It is either an add-in or a (hidden) workbook that is Loaded upon XL's start, which is causing problems. Tools-Addins and uncheck all Addins. Write down which ones were selected. Now close Excel and then reopen. If it is working then one of the Addins was causing the problem. Add them back one at a time, closing and opening Excel each time until you find it. If this didn't stop the problem, then the problem is a file in your xlStart directory. Any file in there Is loaded when you start Excel. Remove the files out of that folder and open Excel to see if the problem is gone. If it is then add them back one at a time, closing and opening Excel each time until you find it.

Do you use some software like "Grammar check or something"? If yes, remove it out, restate computer, and your excel will be back to normal.

Sorry i was wrong, It is not from those software.
Actually, it's from Skype.
Excel works when you don't open browser like Google Chrome or Fire Fox, (or may be IE)
The solution is open Google Chrome, Right click on the top of page choose Task Manager, and then choose Skype, click End Process.

Excel will be back