PowerShell · xtqqczze · Oct 5, 2025 · Oct 5, 2025 · Oct 5, 2025
@@ -28,34 +28,41 @@ public class GetUptimeCommand : PSCmdlet
         /// </summary>
         protected override void ProcessRecord()
         {
-            // Get-Uptime throw if IsHighResolution = false
-            // because stopwatch.GetTimestamp() return DateTime.UtcNow.Ticks
-            // instead of ticks from system startup.
-            // InternalTestHooks.StopwatchIsNotHighResolution is used as test hook.
-            if (Stopwatch.IsHighResolution && !InternalTestHooks.StopwatchIsNotHighResolution)
+            switch (ParameterSetName)
             {
-                TimeSpan uptime = TimeSpan.FromSeconds(Stopwatch.GetTimestamp() / Stopwatch.Frequency);
-
-                switch (ParameterSetName)
-                {
-                    case TimespanParameterSet:
-                        // return TimeSpan of time since the system started up
-                        WriteObject(uptime);
-                        break;
-                    case SinceParameterSet:
-                        // return Datetime when the system started up
-                        WriteObject(DateTime.Now.Subtract(uptime));
-                        break;
-                }
-            }
-            else
-            {
-                WriteDebug("System.Diagnostics.Stopwatch.IsHighResolution returns 'False'.");
-                Exception exc = new NotSupportedException(GetUptimeStrings.GetUptimePlatformIsNotSupported);
-                ThrowTerminatingError(new ErrorRecord(exc, "GetUptimePlatformIsNotSupported", ErrorCategory.NotImplemented, null));
+                case TimespanParameterSet:
+                    ProcessTimespanParameterSet();
+                    break;
+                case SinceParameterSet:
+                    ProcessSinceParameterSet();
+                    break;
             }
         }
 
+        /// <summary>
+        /// Process the Timespan parameter set.
+        /// </summary>
+        /// <remarks>
+        /// Outputs the time of the last system boot as a <see cref="TimeSpan"/>.
+        /// </remarks>
+        private void ProcessTimespanParameterSet()
+        {
+            TimeSpan result = TimeSpan.FromMilliseconds(Environment.TickCount64);
+            WriteObject(result);
+        }
+
+        /// <summary>
+        /// Process the Since parameter set.
+        /// </summary>
+        /// <remarks>
+        /// Outputs the time elapsed since the last system boot as a <see cref="DateTime"/>.
+        /// </remarks>
+        private void ProcessSinceParameterSet()
+        {
+            DateTime result = DateTime.Now.Subtract(TimeSpan.FromMilliseconds(Environment.TickCount64));
+            WriteObject(result);
+        }
+
         /// <summary>
         /// Parameter set name for Timespan OutputType.
         /// </summary>

@@ -1644,8 +1644,6 @@ public static class InternalTestHooks
 
         // It's useful to test that we don't depend on the ScriptBlock and AST objects and can use a re-parsed version.
         internal static bool IgnoreScriptBlockCache;
-        // Simulate 'System.Diagnostics.Stopwatch.IsHighResolution is false' to test Get-Uptime throw
-        internal static bool StopwatchIsNotHighResolution;
         internal static bool DisableGACLoading;
         internal static bool SetConsoleWidthToZero;
         internal static bool SetConsoleHeightToZero;

@@ -1,22 +1,6 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 Describe "Get-Uptime" -Tags "CI" {
-    BeforeAll {
-        $IsHighResolution = [system.diagnostics.stopwatch]::IsHighResolution
-        # Skip Get-Uptime test if IsHighResolution = false
-        # because stopwatch.GetTimestamp() return DateTime.UtcNow.Ticks
-        # instead of ticks from system startup
-        if ( ! $IsHighResolution )
-        {
-            $origDefaults = $PSDefaultParameterValues.Clone()
-            $PSDefaultParameterValues['it:skip'] = $true
-        }
-    }
-    AfterAll {
-        if ( ! $IsHighResolution ){
-            $global:PSDefaultParameterValues = $origDefaults
-        }
-    }
     It "Get-Uptime return timespan (default -Timespan)" {
         $upt = Get-Uptime
         $upt | Should -BeOfType Timespan
@@ -25,15 +9,4 @@ Describe "Get-Uptime" -Tags "CI" {
         $upt = Get-Uptime -Since
         $upt | Should -BeOfType DateTime
     }
-    It "Get-Uptime throw if IsHighResolution == false" {
-        # Enable the test hook
-        [system.management.automation.internal.internaltesthooks]::SetTestHook('StopwatchIsNotHighResolution', $true)
-
-	try {
-            { Get-Uptime } | Should -Throw -ErrorId "GetUptimePlatformIsNotSupported,Microsoft.PowerShell.Commands.GetUptimeCommand"
-	} finally {
-            # Disable the test hook
-            [system.management.automation.internal.internaltesthooks]::SetTestHook('StopwatchIsHighResolutionIsFalse', $false)
-	}
-    }
 }