Hi Bigfan, I have the Hue lights and use them with f.lux. I use a windows desktop too and I didn't have my speakers plugged in when I first synced the hub. I just imagined it was like syncing anything else - once you press the button you've got anywhere from 60 to 30 seconds to pair the other device. So once I checked the box and clicked done in f.lux, I rushed over to my hub and pressed the button. It worked, but every now and then f.lux will not take over the system. A workaround is to check the box and click done again whenever it doesn't and that usually fixes it until it stops working again. So maybe try that.