I received an email from Microsoft telling me to use the serial for Media Center that I had, before the 31. of January. So that's what I did, but when my PC startet up, it told me that my copy of Windows could not be activated. However, my copy WAS activated before the upgrade, so what could have gone wrong? I got this error: 0xC004C4Aa I tried activating offline (by phone) and that worked. But now my copy is activated with the Media Center-license, and not the one I installed Win8 with. Will this have any effect?