I have the same issue. New PCs come with Win10 and I can’t install antivirus I pay for… >:( >:(
Avast guys, aren’t you aware that Win10 is released since August ? Don’t you think it should be your n°1 priority ? ???

For my part, I’m already looking for another antivirus, I won’t start again with Avast when my licences expires in February 2016.