If Copy and Paste stopped working, download GetOpenClipboardWindow and fix your Clipboard
Sometimes you may find that copy and paste no longer function, when you try to copy files or folders, even when you try to copy and paste some text in your notepad or other applications. Both functions are dead!
Although this can be caused by a setting in iobit Advanced System Care (unchecking the RAM cleaning option will work in that case), it is true that the problem might lie in some other application.
The best thing you can do, especially if you don’t even use iobit’s program, is to get this tiny utility called GetOpenClipboardWindow; it will try to open the Windows clipboard, and if the clipboard is dead, as is now the case, it will let you know what application has blocked it.
When you run this utility it will first give you the error message that it receives from the clipboard. Press OK and in the second card it will let you know what application blocks the clipboard. Usually closing this application fixes the problem. In my case the problem came from Windows Explorer. When I closed all the open instances of Explorer, copy and paste started to work again – in Windows Explorer and everywhere!
You may not even have to close the offending application, if the problem disappears just by running this utility!