diff --git a/.gitignore b/.gitignore
index 5bb8b02..bcf4b29 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,3 +33,6 @@ GodotEnv.sln.DotSettings.user
 
 # File-based project format
 *.iws
+
+### Visual Studio ###
+.vs/
diff --git a/GodotEnv.Tests/src/common/clients/FileClientTest.cs b/GodotEnv.Tests/src/common/clients/FileClientTest.cs
index 4b017c3..98891bd 100644
--- a/GodotEnv.Tests/src/common/clients/FileClientTest.cs
+++ b/GodotEnv.Tests/src/common/clients/FileClientTest.cs
@@ -42,6 +42,7 @@ public TestJsonModel(string name) {
   [Fact]
   public void InitializesLinux() {
     FileClient.IsOSPlatform = (platform) => platform == OSPlatform.Linux;
+    FileClient.ProcessorArchitecture = Architecture.X64;
     var fs = GetFs('/');
     var computer = new Mock<IComputer>();
     var client = new FileClient(fs.Object, computer.Object, new Mock<IProcessRunner>().Object);
@@ -50,12 +51,15 @@ public void InitializesLinux() {
     client.OSFamily.ShouldBe(OSFamily.Unix);
     client.Separator.ShouldBe('/');
     client.OS.ShouldBe(OSType.Linux);
+    client.Processor.ShouldBe(ProcessorType.other);
     FileClient.IsOSPlatform = FileClient.IsOSPlatformDefault;
+    FileClient.ProcessorArchitecture = FileClient.ProcessorArchitectureDefault;
   }
 
   [Fact]
   public void InitializesMacOS() {
     FileClient.IsOSPlatform = (platform) => platform == OSPlatform.OSX;
+    FileClient.ProcessorArchitecture = Architecture.X64;
     var fs = GetFs('/');
     var computer = new Mock<IComputer>();
     var client = new FileClient(
@@ -66,7 +70,9 @@ public void InitializesMacOS() {
     client.OSFamily.ShouldBe(OSFamily.Unix);
     client.Separator.ShouldBe('/');
     client.OS.ShouldBe(OSType.MacOS);
+    client.Processor.ShouldBe(ProcessorType.other);
     FileClient.IsOSPlatform = FileClient.IsOSPlatformDefault;
+    FileClient.ProcessorArchitecture = FileClient.ProcessorArchitectureDefault;
   }
 
   [Fact]
@@ -82,19 +88,42 @@ public void InitializesWindows() {
     client.OSFamily.ShouldBe(OSFamily.Windows);
     client.Separator.ShouldBe('\\');
     client.OS.ShouldBe(OSType.Windows);
+    client.Processor.ShouldBe(ProcessorType.arm64);
     FileClient.IsOSPlatform = FileClient.IsOSPlatformDefault;
   }
 
+  [Fact]
+  public void InitializesWindowsArm() {
+    FileClient.IsOSPlatform = (platform) => platform == OSPlatform.Windows;
+    FileClient.ProcessorArchitecture = Architecture.Arm64;
+    var fs = GetFs('\\');
+    var computer = new Mock<IComputer>();
+    var client = new FileClient(
+      fs.Object, computer.Object, new Mock<IProcessRunner>().Object
+    );
+    client.ShouldBeAssignableTo<IFileClient>();
+    client.Files.ShouldBe(fs.Object);
+    client.OSFamily.ShouldBe(OSFamily.Windows);
+    client.Separator.ShouldBe('\\');
+    client.OS.ShouldBe(OSType.Windows);
+    client.Processor.ShouldBe(ProcessorType.arm64);
+    FileClient.IsOSPlatform = FileClient.IsOSPlatformDefault;
+    FileClient.ProcessorArchitecture = FileClient.ProcessorArchitectureDefault;
+  }
+
   [Fact]
   public void InitializesUnknownOS() {
     FileClient.IsOSPlatform = (platform) => false;
+    FileClient.ProcessorArchitecture = Architecture.X64;
     var fs = GetFs('\\');
     var computer = new Mock<IComputer>();
     var client = new FileClient(
       fs.Object, computer.Object, new Mock<IProcessRunner>().Object
     );
     client.OS.ShouldBe(OSType.Unknown);
+    client.Processor.ShouldBe(ProcessorType.other);
     FileClient.IsOSPlatform = FileClient.IsOSPlatformDefault;
+    FileClient.ProcessorArchitecture = FileClient.ProcessorArchitectureDefault;
   }
 
   [Fact]
diff --git a/GodotEnv.Tests/src/features/godot/models/GodotEnvironmentTest.cs b/GodotEnv.Tests/src/features/godot/models/GodotEnvironmentTest.cs
index 0193800..d6c898b 100644
--- a/GodotEnv.Tests/src/features/godot/models/GodotEnvironmentTest.cs
+++ b/GodotEnv.Tests/src/features/godot/models/GodotEnvironmentTest.cs
@@ -1,5 +1,6 @@
 namespace Chickensoft.GodotEnv.Tests.features.godot.models;
 
+using Chickensoft.GodotEnv.Common.Models;
 using Chickensoft.GodotEnv.Features.Godot.Models;
 using Common.Clients;
 using Common.Utilities;
@@ -37,6 +38,8 @@ public void GetsExpectedMacMonoDownloadUrl() {
 
   [Fact]
   public void GetsExpectedWindowsDownloadUrl() {
+    fileClient.Setup(f => f.Processor).Returns(ProcessorType.other);
+
     var platform = new Windows(fileClient.Object, computer.Object);
 
     var downloadUrl = platform.GetDownloadUrl(version4, false, false);
@@ -48,6 +51,8 @@ public void GetsExpectedWindowsDownloadUrl() {
 
   [Fact]
   public void GetsExpectedWindowsMonoDownloadUrl() {
+    fileClient.Setup(f => f.Processor).Returns(ProcessorType.other);
+
     var platform = new Windows(fileClient.Object, computer.Object);
 
     var downloadUrl = platform.GetDownloadUrl(version4, true, false);
@@ -57,6 +62,32 @@ public void GetsExpectedWindowsMonoDownloadUrl() {
     downloadUrl.ShouldBe(GetExpectedDownloadUrl(version3, "stable_mono_win64"));
   }
 
+  [Fact]
+  public void GetsExpectedWindowsArmDownloadUrl() {
+    fileClient.Setup(f => f.Processor).Returns(ProcessorType.arm64);
+
+    var platform = new Windows(fileClient.Object, computer.Object);
+
+    var downloadUrl = platform.GetDownloadUrl(version4, false, false);
+    downloadUrl.ShouldBe($"{GodotEnvironment.GODOT_URL_PREFIX}4.1.2-stable/Godot_v4.1.2-stable_windows_arm64.exe.zip");
+
+    downloadUrl = platform.GetDownloadUrl(version3, false, false);
+    downloadUrl.ShouldBe($"{GodotEnvironment.GODOT_URL_PREFIX}{version3.VersionString}-stable/Godot_v{version3.VersionString}-stable_windows_arm64.exe.zip");
+  }
+
+  [Fact]
+  public void GetsExpectedWindowsArmMonoDownloadUrl() {
+    fileClient.Setup(f => f.Processor).Returns(ProcessorType.arm64);
+
+    var platform = new Windows(fileClient.Object, computer.Object);
+
+    var downloadUrl = platform.GetDownloadUrl(version4, true, false);
+    downloadUrl.ShouldBe(GetExpectedDownloadUrl(version4, "stable_mono_windows_arm64"));
+
+    downloadUrl = platform.GetDownloadUrl(version3, true, false);
+    downloadUrl.ShouldBe(GetExpectedDownloadUrl(version3, "stable_mono_windows_arm64"));
+  }
+
   [Fact]
   public void GetsExpectedLinuxDownloadUrl() {
     var platform = new Linux(fileClient.Object, computer.Object);
diff --git a/GodotEnv/src/common/clients/FileClient.cs b/GodotEnv/src/common/clients/FileClient.cs
index 50d7e38..cad65df 100644
--- a/GodotEnv/src/common/clients/FileClient.cs
+++ b/GodotEnv/src/common/clients/FileClient.cs
@@ -31,6 +31,9 @@ public interface IFileClient {
   /// <summary>The operating system type.</summary>
   OSType OS { get; }
 
+  /// <summary>The process architecture type.</summary>
+  ProcessorType Processor { get; }
+
   /// <summary>Path directory separator.</summary>
   char Separator { get; }
 
@@ -309,6 +312,7 @@ public class FileClient : IFileClient {
   public IProcessRunner ProcessRunner { get; }
   public OSFamily OSFamily { get; }
   public OSType OS { get; }
+  public ProcessorType Processor { get; }
   public char Separator { get; }
 
   // Shims for testing.
@@ -319,6 +323,12 @@ public class FileClient : IFileClient {
   public static Func<OSPlatform, bool> IsOSPlatform { get; set; } =
     IsOSPlatformDefault;
 
+  public static Architecture ProcessorArchitectureDefault { get; } =
+    RuntimeInformation.ProcessArchitecture;
+
+  public static Architecture ProcessorArchitecture { get; set; } =
+    ProcessorArchitectureDefault;
+
   public string UserDirectory => Path.TrimEndingDirectorySeparator(
     Environment.GetFolderPath(
       Environment.SpecialFolder.UserProfile,
@@ -353,6 +363,9 @@ public FileClient(
         : IsOSPlatform(OSPlatform.Windows)
           ? OSType.Windows
           : OSType.Unknown;
+    Processor = ProcessorArchitecture == Architecture.Arm64
+      ? ProcessorType.arm64
+      : ProcessorType.other;
   }
 
   public string Sanitize(string path) =>
diff --git a/GodotEnv/src/common/models/ProcessorType.cs b/GodotEnv/src/common/models/ProcessorType.cs
new file mode 100644
index 0000000..f58e84e
--- /dev/null
+++ b/GodotEnv/src/common/models/ProcessorType.cs
@@ -0,0 +1,11 @@
+namespace Chickensoft.GodotEnv.Common.Models;
+
+/// <summary>
+/// Processor architecture type.
+/// </summary>
+public enum ProcessorType {
+  /// <summary>arm64.</summary>
+  arm64,
+  /// <summary>Other.</summary>
+  other,
+}
diff --git a/GodotEnv/src/features/godot/models/Windows.cs b/GodotEnv/src/features/godot/models/Windows.cs
index 4d67192..81fd3be 100644
--- a/GodotEnv/src/features/godot/models/Windows.cs
+++ b/GodotEnv/src/features/godot/models/Windows.cs
@@ -3,19 +3,25 @@ namespace Chickensoft.GodotEnv.Features.Godot.Models;
 using System.IO.Abstractions;
 using System.Threading.Tasks;
 using Chickensoft.GodotEnv.Common.Clients;
+using Chickensoft.GodotEnv.Common.Models;
 using Chickensoft.GodotEnv.Common.Utilities;
 
 public class Windows : GodotEnvironment {
   public Windows(IFileClient fileClient, IComputer computer)
     : base(fileClient, computer) { }
 
+  private string ProcessorArchitecture =>
+    FileClient.Processor == ProcessorType.arm64
+      ? "windows_arm64"
+      : "win64";
+
   public override string ExportTemplatesBasePath =>
     FileClient.GetFullPath(
       FileClient.Combine(FileClient.UserDirectory, "\\AppData\\Roaming\\Godot")
     );
 
   public override string GetInstallerNameSuffix(bool isDotnetVersion, SemanticVersion version) =>
-    isDotnetVersion ? "_mono_win64" : "_win64.exe";
+    isDotnetVersion ? $"_mono_{ProcessorArchitecture}" : $"_{ProcessorArchitecture}.exe";
 
   public override Task<bool> IsExecutable(IShell shell, IFileInfo file) =>
     Task.FromResult(file.Name.ToLower().EndsWith(".exe"));
@@ -27,13 +33,13 @@ public override string GetRelativeExtractedExecutablePath(
   ) {
     var fsVersionString = GetFilenameVersionString(version);
     var name = fsVersionString +
-      $"{(isDotnetVersion ? "_mono" : "")}_win64.exe";
+      $"{(isDotnetVersion ? "_mono" : "")}_{ProcessorArchitecture}.exe";
 
     // Both versions extract to a folder. The dotnet folder name is different
     // from the non-dotnet folder name :P
 
     if (isDotnetVersion) {
-      return FileClient.Combine(fsVersionString + "_mono_win64", name);
+      return FileClient.Combine(fsVersionString + $"_mono_{ProcessorArchitecture}", name);
     }
 
     // There is no subfolder for non-dotnet versions.
@@ -44,6 +50,6 @@ public override string GetRelativeGodotSharpPath(
     SemanticVersion version,
     bool isDotnetVersion
   ) => FileClient.Combine(
-    GetFilenameVersionString(version) + "_mono_win64", "GodotSharp"
+    GetFilenameVersionString(version) + $"_mono_{ProcessorArchitecture}", "GodotSharp"
   );
 }