For those unfortunate Windows 8.1 users suffering WiFi problems, of which I was one, the only solution I have is for HP Computer users. I had another problem of a different nature with my HP Envy DV7 which necessitated a factory install. Having contacted HP UK direct, from where I purchased the machine, this was advised as my solution. The Good news is that HP Reinstalls revert back to Windows 8, as HP does not recognize 8.1 as an operation system, Hey Presto now WiFi problems have disappeared and seems we are back to normal, pre Windows8.1. I have No intention of upgrading either, at least until Microsoft has resolved the situation.
Good Luck with this
Chermac