This is a quirky problem with a few answers depending on the source of the issue. Before you try any of these, just make sure your Esc key isn't stuck down. That's the easiest fix
■ General Fix #1: Go to registry HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\. Look for and delete the graphic number ( a square or an L) located before zone number 0. If it's not there, this isn't your fix.
■ General Fix #2: Look for "Send to Bluetooth" add-in under each office program and delete it. Find it under Options, Add-ins. If it's not listed, you don't have the add-in and it's not the problem. If you see it, go to Manage, Select COM add-ins and click Go. Check the box next to the add in and click Remove.
■ General Fix #3: Click the Start/Windows button, Type Go to Start (Start/Run) type the following in the search box: cmd /c “echo off | clip” (including the quotes) then hit Enter. Note that there is a space between "cmd" and "/" but nowhere else. I keep a copy of this command in my stickies on ClipX so I don't have to go back and find it every time this happens. If you prefer, you can create a desktop shortcut that does the same thing. Just right-click on any frees space on the desktop and select New, Shortcut. Type the command into the location box. Click Next, name the shortcut and Finish.
■ General Fix #4: Make sure you are using the most recent version of Flash Player. If not, update it.
■If you use Remote Desktop: Open task manager, end the RDPCLIP.EXE process, and then restart the task. To restart the task, go to applications tab, click new task and type in rdpclip.exe.
■If you use Advanced System Care 5 from IOBIT (ASC): Open the ASC Toolbox. Under Optimize, Smart RAM, Settings, uncheck "Clean Clipboard"
■If You use Skype: Delete the Add-ins for IE and Firefox (Skype might also cause problems when using the Click to Call feature in Chrome). Some have had luck uninstalling Skype, then re-installing the latest version.
■If the problem occurs in IE: Go to Internet Options, Advanced tab. Click Reset under Reset Internet Explorer Settings. Click OK. This fixes problems associated with malware.
■If you use Microsoft visual C++ 2005 (needed by some programs to work): Try uninstalling it if you don't absolutely need it. If you do need it, try General Fix #4 (the one that ultimately worked for me).
■If you use Adobe Acrobat: Try uninstalling it. Might need to use Foxit Reader instead.