The title says it all. I currently have installed Windows 8.1 VL with all my programs setup as I would like. I have an unused 8.1 WMC key and now realise I need WMC on this computer. My question is: Is it possible, without reinstalling, to switch from 8.1 VL to 8.1 WMC or 8.1 Retail so that I can upgrade to WMC and use my WMC key? Thanks for your help.