How to change default program to open magnet link in windows?

Open μTorrent. Go to preferences from options menu. Select general. Click the button Associate with torrent files. Your problem is over.

You need to change the "Handlers" setting inside the Chrome Settings.

Click the Chrome menu on the browser toolbar.

Select Settings > Show advanced settings.

In the "Privacy" section, click Content settings.

In the dialog that appears, find the “Handlers” section. Click Manage handlers.

Use the drop-down menu next to a listed protocol to select the web service that should be used by default.

P.S - This answer was for a pretty old version of Chrome. The settings have changed since then and I don't use Chrome anymore, so maybe try some of the other answers.

1. Press Win + R, type regedit and press OK.

2. Browse to the following location:

   HKEY_CLASSES_ROOT\Magnet\shell\open\command
   

3. Double-click the default location and change the data section to:

   "C:\Program Files (x86)\uTorrent\uTorrent.exe" "%L"