diff --git a/System.Test/ShutdownTest.cs b/System.Test/ShutdownTest.cs
new file mode 100644
index 0000000..313dc33
--- /dev/null
+++ b/System.Test/ShutdownTest.cs
@@ -0,0 +1,244 @@
+using FrApp42.System.Computer.Shutdown;
+
+namespace System.Test
+{
+	[TestClass]
+	public class ShutdownTest
+	{
+		private readonly string _hostname = "machine.local";
+
+		[TestMethod]
+		public void ClassicShutdown()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetMachine(_hostname)
+				.ShutdownComputer();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /m {_hostname} /s";
+
+			Assert.AreEqual(expectedCommand, command, "The generated command does not match the expected command.");
+		}
+
+		[TestMethod]
+		public void LogOffUser()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.LogoutUser();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /l";
+
+			Assert.AreEqual(expectedCommand, command, "The generated command does not match the expected command.");
+		}
+
+		[TestMethod]
+		public void ShutdownAndSignOnAuto()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.ShutdownAndSignOn();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /sg";
+
+			Assert.AreEqual(expectedCommand, command, "The generated command does not match the expected command.");
+		}
+
+		[TestMethod]
+		public void TimeOutAndComment()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetMachine(_hostname)
+				.SetTimeOut(60)
+				.SetComment("Scheduled maintenance")
+				.ShutdownComputer();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /m {_hostname} /t 60 /c \"Scheduled maintenance\" /s";
+
+			Assert.AreEqual(expectedCommand, command, "The generated command does not match the expected command.");
+		}
+
+		[TestMethod]
+		public void RebootComputer()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetMachine(_hostname)
+				.Reboot();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /m {_hostname} /r";
+
+			Assert.AreEqual(expectedCommand, command, "The generated command does not match the expected command.");
+		}
+
+		[TestMethod]
+		public void HibernateComputer()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetMachine(_hostname)
+				.Hibernate();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /m {_hostname} /h";
+
+			Assert.AreEqual(expectedCommand, command, "The generated command does not match the expected command.");
+		}
+
+		[TestMethod]
+		public void SoftShutdown()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetMachine(_hostname)
+				.ShutdownComputer()
+				.Soft();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /m {_hostname} /s /soft";
+
+			Assert.AreEqual(expectedCommand, command, "The generated command does not match the expected command.");
+		}
+
+		[TestMethod]
+		public void OpenBootOptionsTest()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetMachine(_hostname)
+				.Reboot()
+				.OpenBootOptions();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /m {_hostname} /r /o";
+
+			Assert.AreEqual(expectedCommand, command, "The generated command does not match the expected command.");
+		}
+
+		[TestMethod]
+		public void ForceShutdownComputer()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetMachine(_hostname)
+				.ShutdownComputer()
+				.ForceShutdown();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /m {_hostname} /s /f";
+
+			Assert.AreEqual(expectedCommand, command, "The generated command does not match the expected command.");
+		}
+
+		[TestMethod]
+		public void ShutdownWithComment()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetMachine(_hostname)
+				.ShutdownComputer()
+				.SetComment("End of day shutdown");
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /m {_hostname} /s /c \"End of day shutdown\"";
+
+			Assert.AreEqual(expectedCommand, command, "The generated command does not match the expected command.");
+		}
+
+		[TestMethod]
+		public void LogoutNotWithMachine()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetMachine(_hostname)
+				.LogoutUser();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /m {_hostname}";
+
+			Assert.AreEqual(expectedCommand, command, "The command should not contain /l when /m is present.");
+		}
+
+		[TestMethod]
+		public void LogoutNotWithTimeout()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetTimeOut(60)
+				.LogoutUser();
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /t 60";
+
+			Assert.AreEqual(expectedCommand, command, "The command should not contain /l when /t is present.");
+		}
+
+		[TestMethod]
+		public void MachineNotWithLogout()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.LogoutUser()
+				.SetMachine(_hostname);
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /l";
+
+			Assert.AreEqual(expectedCommand, command, "The command should not contain /m when /l is present.");
+		}
+
+		[TestMethod]
+		public void TimeoutNotWithLogout()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.LogoutUser()
+				.SetTimeOut(60);
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /l";
+
+			Assert.AreEqual(expectedCommand, command, "The command should not contain /t when /l is present.");
+		}
+
+		[TestMethod]
+		public void NoDuplicateArguments()
+		{
+			Shutdown shutdown = new();
+			shutdown
+				.SetMachine(_hostname)
+				.SetMachine(_hostname);
+
+			string command = shutdown.GetCommand();
+			string expectedCommand = $" /m {_hostname}";
+
+			Assert.AreEqual(expectedCommand, command, "The command should not contain duplicated /m arguments.");
+
+			shutdown = new Shutdown();
+			shutdown
+				.SetTimeOut(60)
+				.SetTimeOut(60);
+
+			command = shutdown.GetCommand();
+			expectedCommand = $" /t 60";
+
+			Assert.AreEqual(expectedCommand, command, "The command should not contain duplicated /t arguments.");
+
+			shutdown = new Shutdown();
+			shutdown
+				.ShutdownComputer()
+				.ShutdownComputer();
+
+			command = shutdown.GetCommand();
+			expectedCommand = $" /s";
+
+			Assert.AreEqual(expectedCommand, command, "The command should not contain duplicated /s arguments.");
+		}
+	}
+}
diff --git a/System.Test/System.Test.csproj b/System.Test/System.Test.csproj
new file mode 100644
index 0000000..3f37dea
--- /dev/null
+++ b/System.Test/System.Test.csproj
@@ -0,0 +1,27 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+    <PackageReference Include="MSTest.TestAdapter" Version="3.1.1" />
+    <PackageReference Include="MSTest.TestFramework" Version="3.1.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\System\System.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Microsoft.VisualStudio.TestTools.UnitTesting" />
+  </ItemGroup>
+
+</Project>
diff --git a/Tools.sln b/Tools.sln
index d82f748..f486d95 100644
--- a/Tools.sln
+++ b/Tools.sln
@@ -7,6 +7,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System", "System\System.csp
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Web", "Web\Web.csproj", "{3872357E-B751-4C1B-AFD7-E4883E2FBB4C}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "System.Test", "System.Test\System.Test.csproj", "{1501A81F-3308-4471-BCDF-113AC9BF13EA}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -21,6 +23,10 @@ Global
 		{3872357E-B751-4C1B-AFD7-E4883E2FBB4C}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{3872357E-B751-4C1B-AFD7-E4883E2FBB4C}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{3872357E-B751-4C1B-AFD7-E4883E2FBB4C}.Release|Any CPU.Build.0 = Release|Any CPU
+		{1501A81F-3308-4471-BCDF-113AC9BF13EA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{1501A81F-3308-4471-BCDF-113AC9BF13EA}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{1501A81F-3308-4471-BCDF-113AC9BF13EA}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{1501A81F-3308-4471-BCDF-113AC9BF13EA}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE