Sorry to create a thread as I'm sure it has been covered so please just point me in the right direction. I installed Win8 on my kids computer and cannot recall what I did to activate it. I think i used a generic key and then went to add features and upgraded it to WMC using the free WMC keys, back when WMC keys activated Win8. Do i just download the update from the store or use a ISO to install 8.1 using generic key then go to add features and use my WMC key again to get it activated?
If your Win8 WMC used a legitimate free WMC key and is currently activated, then you can download from the store to upgrade to 8.1 and it will still be activated.
This is true only when you are installing from ISO. If you have an activated Windows 8 Pro WMC installation, you can upgrade it directly to Windows 8.1 Pro WMC via the Windows Store. You will not have Windows 8.1 Pro (without WMC) at any point. The resulting Windows 8.1 Pro WMC will be automatically activated.
I upgraded 3 Windows 8 WMC installations activated with free WMC keys from the Windows Store to Windows 8.1 Pro WMC and they were all automatically activated. Unless you have extremely fast internet connection it is a slow process. The download is a little over 3 GB.