I had the toolbox installed but a couple of weeks ago when I opened excel, the toolbox tab had disappeared from Excel. I tried all the things already mentioned on the forum but nothing worked. So I thought to uninstall the program and reinstall. The only problem is that when I try and install the new version, it gives me the notice (see image) that office needs to be closed prior to installation. All office apps are closed but installation does not proceed. The execution software simply repeats the same message. Anyone else experiencing the same? What can I do?