EITHER The default gateway is not available, OR Network adapter is disabled

If the troubleshooter is causing more problems than it is solving, stop using it. Now isolate why your wireless is not working.
Some known reasons:
A laptop wireless adapter is designed to stop working if battery power drops below a certain percent. To eliminate this as the problem simply keep the charger plugged in to prevent low battery. Most laptop users go through this experience. The reason for such a design is to prevent downloads from failing part of the way thru the process.
A partial update will brick a laptop.

Next, move very close to the wireless router with the adapter plugged in and check signal strength. If you never drop out when close then signal strength is the problem.

Lastly, review what you may have been doing on line when you experienced drop out. Is it site sensitive?

It just sounds like the drivers are NOT capable of POWER saving/RESUME. Turn off any power saving, and untick any boxes that might say something like allow this port to be switched off to save power(use less battery/extend battery life) thus it may make a difference when on battery or on psu power. See your Power Scheme advanced settings. Typically a side effect might be your router keeps giving your pc a NEW(next) IP and therefore all the software gets mixed up. You can sometimes circumvent that in the ROUTER by ticking a box alongside your CONNECTED station(your pc in its list of stations) which might say ALWAYS GIVE THIS PC WITH THIS MAC ADDRESS this IP(ie keep it as the same IP and never give it any other IP. If that makes sense. Then the software doesn't mind windows drivers that turn on/off ports willy nilly and **** things up.