I cant connect to my router

Hey i cant connect to my router from my pc upstairs about a week ago this happened my internet slowed down then suddenly stopped on my pc but could find it on my phone so i disconnected. From the network and try to reconnect but i wasnt letting me connect it prompted me woth my password for router and windows cannot connect to sky***** so i diagnose connection it says wireless association failed becuase windows did not receive any respone from the wireless routed or access point... My router is from sky my wireless adapter is netgear wg111v2 and software is netgear wireless assistsnt many help is appreicated since sky spent an hour on th phoe to tell me they cant help.