So I just tried to open a .docx file using Word, and it asked for a product key. I haven't purchased Microsoft office in at least 4 years, so what gives? I don't have any product key any more, nor any proof of purchase or anything like that. Furthermore, Excel and Powerpoint stop responding.
I was using Office within the past month. The only thing that has changed is that I did swap my hard drive out for a different one. Could that be an issue? What can I do?