GPS/location functionality is provided using Windows Location services, which must be enabled in order the app to access these services.
The link below describes how to configure Location Services on Windows 10:
http://www.howtogeek.com/221869/how-to-disable-or-configure-location-tracking-in-windows-10
See the link below for enabling Windows Location Platform on Windows 7 and 8:
http://www.techsupportalert.com/content/how-enable-or-disable-location-sensing-windows-7-and-8.htm
For Windows 7 devices, you will need a location sensor for use with Windows Location Platform. The link below outlines how to install the free Geosense sensor:
http://www.howtogeek.com/howto/12131/find-your-computers-location-with-windows-7-and-geosense/
If GPS accuracy is important to your needs, then we strongly recommend using Windows devices with onboard GPS chips to receive accurate location regardless of network connectivity. Windows 10 devices are also best in terms of ensuring compatibility.
For devices without an onboard GPS chip, Windows will use network information such as IP addresses to determine an approximate user location (usually only accurate to around 15 Miles, but occasionally can be very inaccurate).
Note that the GPS chip on a tethered/hot-spot phone is NOT used, since the chip is in a separate device. Similarly, an externally attached GPS receiver is not guaranteed to work, since there could be any number of Windows compatibility or driver issues involved beyond our control.
Hence our advice on using devices with integrated/onboard GPS if location accuracy is required.