Getting Wifi working on Windows if your machine doesn't have it built in can be a nightmare. I have a number of cheap dongles. Plug them into the machine when running Linux, it detects the chipset, possibly loads non-free firmware (and it is relatively easy to find the right firmware package), and generally it then just works.

I intend to put details of the comparative procedure on Windows here. Part of the problem is that I got the dongles for RaspberryPi's, so don't have a clue where the driver dvd is, nor who the manufacturer is, nor if they have a website with downloadable drivers.

  1. Go to Windows Device Manager (right click on Computer in start menu, select Properties, then select Device Manager on left pane).
  2. Find the device in Other Devices, then select Properties
  3. Go to details pane, select Hardware Ids from the property dropdown.
  4. You will see, e.g. USB\VID_148F&PID_5370&REV_0101 -- take this string and put it into google, or another search engine.

That gives you a good chance of finding something. I found a .cab file via devid.info, copied it to the machine, extracted all the files to a folder, then in the Device Manager right click on the unknown device, click Update Driver Software, select the option to browse your machine, and point it to the folder you unpacked the drivers to.