Laptop drops connection to wireless network randomly.

My daughter has a laptop that keeps losing it's connection to the local wireless network - any local wireless network.
It will connect to any network, using security passwords, but then just drop off, after random amounts of time, ending in the message "The specified network is not available". A complete shutdown and cold start will allow a connection again, briefly.
Everything works fine on wired Ethernet cable.
Toshiba C55-C5241
Broadcom 802.11n Network Adapter

Looking for any potential fixes I have not already found on the interwebs (list below).
When she gets here today I am going to generate a Wireless Network Report (netsh command). Let me know if it would be helpful to see that report.
Tried:

• Updating the driver to the most recent one on the MS Update Catalog
• Making sure "allow the PC to put this device to sleep" is unchecked
• All other wireless devices connect to the LAN fine
• Move the laptop to the same room, withing 10 feet of the router.
• Reset the router
• Problem happens on 3 wireless LAN's.
• Created a Guest network with no security protocols.
• Problem happened before and after the 1903 upgrade
• USB selective Suspend: disabled
• Changed the Scan Valid Interval
• Set WLAN Auto Config in Services to Auto (was on Auto)

You've double-posted, folks won't know which to replay to, not nice.

Start off with is she using her laptop on a public network or her own private network. Public networks are notorious for not enough bandwidth and distance restrictions are crap. If a private network, location, location, location. A lot of factors at work here. She can monitor signals, etc with a tool like inSSIDer - Discover Your WiFi Environment

Berton said:

You've double-posted, folks won't know which to replay to, not nice.

Hi Burton
Yeah I wasn't sure how to best handle this, but there are 2 distinct questions.
In the Hardware thread I am asking the hardware guys a specific question related to this subject on how to test the hardware.
In this thread I am asking the networking dudes for any help regarding the network end of the puzzle.

I thought this would be more clear. Maybe not.

bro67 said:

Start off with is she using her laptop on a public network or her own private network. Public networks are notorious for not enough bandwidth and distance restrictions are crap. If a private network, location, location, location. A lot of factors at work here. She can monitor signals, etc with a tool like inSSIDer - Discover Your WiFi Environment

Love inSSIDer! got that already.
As mentioned, this is a private network (LAN). The home network at my house, and the home network at her house.
And I did tests to eliminate the signal interference possibility.

Keep em coming!