Solving “Btsync:// Protocol Not Available” errors (or how to register a new protocol in Windows)

I have BitTorrent Sync. It was installed a long time ago and automatically updated over the years. I guess the initial installs never registered the Btsync protocol because today I emailed myself a link to a shared folder on my phone and when I clicked the link on the computer nothing happened. I was using Chrome so I tried it under Internet Explorer and Firefox. The former gave the error above, the latter said the address wasn’t understood and explained that it doesn’t know what program to use for the btsync protocol. Good, at least these were clearer on what the issue was. (Moreover Firefox even showed the full address in the address-bar – btsync:// – kudos to it!)

I haven’t added a new protocol/ extension to Windows for a long while, and while I could modify the protocols/ extensions for existing entries under “Default Programs” in the Windows control panel (I am using Windows 8.1 Update 1 by the way) there was no option to add a new protocol. Never mind, it’s possible via the registry. See this link on more details, the upshot of it is that you can create registry keys under HKEY_CLASSES_ROOT to register new protocols or file extensions. Below is what I created for Btsync, copy paste this into a text file with the extension .reg, change the program paths if your installation is in a different folder (quite possible if you have the 64-bit version for instance), then double click the file and say OK to importing it. 

That’s it! Now BitTorrent launches as expected. Hope this helps someone …