I assume you mean you are losing your wireless connectivity to the router from the laptops and that the pc connected to the router still has internet connection ?
Possible problems for loss of wireless connectivity is other wireless kit as you suggest. Have you or your neighbours just bought DECT cordless phones, baby alarms, video senders ? These can cause problems. Also the best channels to use for your laptop in the UK is 1, 6 or 11. Have you tried all of these channels ?
I had problems using channel 10 & 11 but have changed to 1 and wireless connection is now solid.