I have been using my Windows 8 installation for months without any issues.
Recently, Windows has been notifying me about needing to activate even though I have activated in the past. Also, Office 2013 has become unlicensed and features have been deactivated.
I have been able to ignore the activation notices thus far. The activation notices both require the product key so I'll need to do some digging to find those.
Any ideas why this occurred? It seems to have happened immediately after I updated several apps in the Windows store.