'Seems a trip back to the supplier is in order, particularly as it WAS working for 2 weeks and then ceased doing so without any related event.
Wireless cards can fail. My first laptop connected fine and I thought behaved itself. Until I tried running it all on battery alone.
After a minute or two the laptop disconnected and I had to repeat the I.E. opening and so on.
All apps and programs behaved normally showing it was not a faulty battery.
The card must have had a component on the edge of permitted tolerance.
The retailer apologised, sent a replacement card, described how to replace it, and two years later it still works fine.