[Paul]

Will also depend on what service tier you are on, there are currently issues with Connect. You need to use ethernet temporarily to check the connection stability to isolate if it is a wireless issue or a connection issue. Also you will need to check your SNR stats on the router when the connection is coming and going to see if it's line related.
If it's wireless then you may want to turn UPnP off in the router until the new firmware is released as it is buggy in the old V1 netgear sent out. If you are on a new V2 router (black or dark grey) then it shouldn't be an issue.
Also make sure windows is controlling the wireless device on the PC, some manufacturer control software misbehaves with the router.