The Office 2013 Pro Plus had to be reinstalled. But after that, every time when a program was initiated, a warning screen appears to request the product key. The key that worked the first time cannot be accepted by saying that it's for corporate or institutional use. I have tried every trick by going through ...>Office15 and cscript ospp.vbs /... and inputting various commands, but none of them worked. Are there any ways to get over this problem?