Having the same issue here, on Windows 8.1 x64. I opted not to scan any plugin folders yet. Just pasting in the serial code took some time. I can get to the Audio tab of preferences (after a few seconds of waiting, and my fan kicking on as if I'm playing a game) but I can't seem to open the "Windows Audio" dropdown to switch to ASIO.
Running an Acer Travelmate P645, i7-4510U CPU and integrated graphics.