Prevented the app from running on Windows 10 version 1803 or higher since ths technique used by this app doesn't work on these versions.

Author: sampalmer

SetDefaultBrowser/DefaultBrowserChanger.cs

@@ -16,6 +16,13 @@ static class DefaultBrowserChanger
         /// </exception>
         public static void Set(Browser browser)
         {
+            // In Windows 10 version 1803, the old control-panel-style Default Programs screen has been replaced with a new one inside the Windows 10 settings app.
+            // However, the Windows 10 settings app cannot be automated without the user seeing it or interacting with it, so that option is unreliable.
+            // Fortunately, someone else has written a better alternative to this app (http://kolbi.cz/blog/?p=396).
+            // So for these reasons, this app won't support this or later versions of Windows.
+            if (OsInfo.Windows10Version >= 1803)
+                throw new EnvironmentException($"This app no longer works in this version of Windows.");
+
             // This is needed since the control panel applet can crash if you give it an empty browser name
             if (String.IsNullOrWhiteSpace(browser.UniqueApplicationName))
                 throw new EnvironmentException($"The given browser's unique application name is blank.");

SetDefaultBrowser/OsInfo.cs

@@ -0,0 +1,32 @@
+using Microsoft.Win32;
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SetDefaultBrowser
+{
+    static class OsInfo
+    {
+        /// <summary>
+        /// Gets the Windows 10 version number as shown in the "About" screen in the settings app.
+        /// This value is also known as the Windows 10 "Release ID".
+        /// </summary>
+        /// <value>
+        /// The version number, such as <c>1803</c> or <c>1703</c>, or <c>null</c> if not running on Windows 10.
+        /// </value>
+        public static int? Windows10Version
+        {
+            get
+            {
+                var versionNumberText = (string)Registry.GetValue(@"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion", "ReleaseId", null);
+                if (versionNumberText == null)
+                    return null;
+
+                return int.Parse(versionNumberText, CultureInfo.InvariantCulture);
+            }
+        }
+    }
+}

SetDefaultBrowser/SetDefaultBrowser.csproj

@@ -59,6 +59,7 @@
     <Compile Include="DesktopProcess.cs" />
     <Compile Include="EnvironmentException.cs" />
     <Compile Include="ListView.cs" />
+    <Compile Include="OsInfo.cs" />
     <Compile Include="ProcessAccessFlags.cs" />
     <Compile Include="ProcessMemoryChunk.cs" />
     <Compile Include="Program.cs" />