Windows: NetSpot is an amazing OS X utility for mapping out Wi-Fi networks, finding spots of poor reception and troubleshooting how to fix them, and now it's available for Windows. Best of all, it's still completely free. Like the Mac version, NetSpot for Windows lets you see all SSID in your vicinity, their operating channels and which ones are interfering with one another. You can list off all of the networks in your vicinity, and use the tool's mapping feature to lay out where the access points are located relative to your current position. The built-in channel and strength analyser can run in the background, so you can map out reception as you move around your house. NetSpot also builds a live heatmap of your signal strength, so you know where you should position your access points or routers for best reception where you want to work (or where you should put your desk for the best reception).
The Windows version is missing a few features though, like the ability to create multiple snapshots and zones per survey project, but they're coming soon. NetSpot supports Windows 7, 8 and 10, and 802.11 a/b/g/n/ac. Hit the link below to check it out.
NetSpot for Windows [NetSpot]