diff --git a/test/jdk/sun/security/mscapi/CngCipher.java b/test/jdk/sun/security/mscapi/CngCipher.java
index b867641e8a5..348fdeef865 100644
--- a/test/jdk/sun/security/mscapi/CngCipher.java
+++ b/test/jdk/sun/security/mscapi/CngCipher.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -22,6 +22,7 @@
  */
 
 import jdk.test.lib.Asserts;
+import jdk.test.lib.util.FileUtils;
 import jdk.test.lib.SecurityTools;
 
 import java.util.Arrays;
@@ -57,7 +58,7 @@ public class CngCipher {
         SecurityTools.keytool("-storetype Windows-MY -genkeypair -alias "
                 + PREFIX + "m -keyalg RSA -dname CN=" + PREFIX + "m");
         // This will generate a CNG key
-        ProcessBuilder pb = new ProcessBuilder("powershell", "-Command",
+        ProcessBuilder pb = new ProcessBuilder(FileUtils.powerShellPath(), "-Command",
                 "New-SelfSignedCertificate",  "-DnsName", PREFIX + "c",
                 // -KeyAlgorithm not supported on Windows Server 2012
                 //"-KeyAlgorithm", "RSA",
diff --git a/test/jdk/sun/security/mscapi/DupAlias.java b/test/jdk/sun/security/mscapi/DupAlias.java
index 84c70cbbee2..bcadb2debe4 100644
--- a/test/jdk/sun/security/mscapi/DupAlias.java
+++ b/test/jdk/sun/security/mscapi/DupAlias.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2023, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -21,6 +21,7 @@
  * questions.
  */
 import jdk.test.lib.Asserts;
+import jdk.test.lib.util.FileUtils;
 import sun.security.tools.keytool.CertAndKeyGen;
 import sun.security.x509.X500Name;
 
@@ -83,7 +84,7 @@ public class DupAlias {
     }
 
     static void ps(String f) throws Exception {
-        ProcessBuilder pb = new ProcessBuilder("powershell", "-Command", f);
+        ProcessBuilder pb = new ProcessBuilder(FileUtils.powerShellPath(), "-Command", f);
         pb.inheritIO();
         if (pb.start().waitFor() != 0) {
             throw new RuntimeException("Failed");
diff --git a/test/jdk/tools/jpackage/helpers/jdk/jpackage/test/WinExecutableIconVerifier.java b/test/jdk/tools/jpackage/helpers/jdk/jpackage/test/WinExecutableIconVerifier.java
index f4468fa9ab0..3967c0131db 100644
--- a/test/jdk/tools/jpackage/helpers/jdk/jpackage/test/WinExecutableIconVerifier.java
+++ b/test/jdk/tools/jpackage/helpers/jdk/jpackage/test/WinExecutableIconVerifier.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2025, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -208,7 +208,7 @@ public final class WinExecutableIconVerifier {
 
         Path extractedIcon = outputDir.resolve(extractedIconFilename + ".bmp");
 
-        Executor.of("powershell", "-NoLogo", "-NoProfile", "-ExecutionPolicy", "Unrestricted",
+        Executor.of(WindowsHelper.PowerShellPath(), "-NoLogo", "-NoProfile", "-ExecutionPolicy", "Unrestricted",
                 "-File", EXTRACT_ICON_PS1.toString(),
                 "-InputExecutable", executable.toAbsolutePath().normalize().toString(),
                 "-OutputIcon", extractedIcon.toAbsolutePath().normalize().toString()
diff --git a/test/jdk/tools/jpackage/helpers/jdk/jpackage/test/WindowsHelper.java b/test/jdk/tools/jpackage/helpers/jdk/jpackage/test/WindowsHelper.java
index 22031d1a7fd..639bd295e57 100644
--- a/test/jdk/tools/jpackage/helpers/jdk/jpackage/test/WindowsHelper.java
+++ b/test/jdk/tools/jpackage/helpers/jdk/jpackage/test/WindowsHelper.java
@@ -306,7 +306,7 @@ public class WindowsHelper {
     }
 
     public static String getExecutableDescription(Path pathToExeFile) {
-        Executor exec = Executor.of("powershell",
+        Executor exec = Executor.of(PowerShellPath(),
                 "-NoLogo",
                 "-NoProfile",
                 "-Command",
@@ -455,7 +455,7 @@ public class WindowsHelper {
         ;
 
         Path getPath() {
-            final var str = Executor.of("powershell", "-NoLogo", "-NoProfile",
+            final var str = Executor.of(PowerShellPath(), "-NoLogo", "-NoProfile",
                     "-NonInteractive", "-Command",
                     String.format("[Environment]::GetFolderPath('%s')", name())
                     ).saveFirstLineOfOutput().execute().getFirstLineOfOutput();
@@ -661,4 +661,11 @@ public class WindowsHelper {
     private static final String USER_SHELL_FOLDERS_REGKEY = "HKCU\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Shell Folders";
 
     private static final int WIN_MAX_PATH = 260;
+
+    public static String PowerShellPath() {
+        String systemRoot = System.getenv("SystemRoot");
+        String suffix = "\\System32\\WindowsPowerShell\\v1.0\\powershell.exe";
+        String fullPath = systemRoot == null ? null : systemRoot + suffix;
+        return (fullPath != null && Files.exists(Path.of(fullPath))) ? fullPath : "powershell";
+    }
 }
diff --git a/test/jdk/tools/jpackage/junit/share/jdk.jpackage/jdk/jpackage/internal/util/CommandOutputControlTest.java b/test/jdk/tools/jpackage/junit/share/jdk.jpackage/jdk/jpackage/internal/util/CommandOutputControlTest.java
index 2ddfbcb5d78..43280de79ad 100644
--- a/test/jdk/tools/jpackage/junit/share/jdk.jpackage/jdk/jpackage/internal/util/CommandOutputControlTest.java
+++ b/test/jdk/tools/jpackage/junit/share/jdk.jpackage/jdk/jpackage/internal/util/CommandOutputControlTest.java
@@ -22,6 +22,8 @@
  */
 package jdk.jpackage.internal.util;
 
+import jdk.jpackage.test.WindowsHelper;
+
 import static java.util.stream.Collectors.joining;
 import static jdk.jpackage.internal.util.CommandOutputControlTestUtils.isInterleave;
 import static jdk.jpackage.internal.util.function.ThrowingConsumer.toConsumer;
@@ -1004,7 +1006,7 @@ public class CommandOutputControlTest {
                     commandSeparator = " && ";
                 }
                 case POWERSHELL -> {
-                    commandline.addAll(List.of("powershell", "-NoProfile", "-Command"));
+                    commandline.addAll(List.of(WindowsHelper.PowerShellPath(), "-NoProfile", "-Command"));
                     commandSeparator = "; ";
                 }
                 default -> {
@@ -1176,7 +1178,7 @@ public class CommandOutputControlTest {
                     // It sends packets every second.
                     // To wait N seconds, it should send N+1 packets.
                     // The "timeout" command works only in a console.
-                    return String.format("(ping -n %d localhost > nul)", sleep.seconds() + 1);
+                    return String.format("(%%SystemRoot%%\\System32\\ping.exe -n %d localhost > nul)", sleep.seconds() + 1);
                 }
                 case POWERSHELL -> {
                     return "Start-Sleep -Seconds " + sleep.seconds();
diff --git a/test/jdk/tools/jpackage/resources/Win8365790Test.ps1 b/test/jdk/tools/jpackage/resources/Win8365790Test.ps1
index 3a7d8c9a90b..ee77fea2a67 100644
--- a/test/jdk/tools/jpackage/resources/Win8365790Test.ps1
+++ b/test/jdk/tools/jpackage/resources/Win8365790Test.ps1
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2025, 2026, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -64,6 +64,9 @@ Add-Type @type
 
 Set-PSDebug -Trace 2
 
+# Ensure system directories are on the PATH for the child process.
+$env:Path = "$env:SystemRoot\System32;$env:SystemRoot;$env:Path"
+
 # Launch the target executable.
 # `-NoNewWindow` parameter will attach the started process to the existing console.
 $childProc = Start-Process -PassThru -NoNewWindow $Executable
diff --git a/test/jdk/tools/jpackage/windows/Win8365790Test.java b/test/jdk/tools/jpackage/windows/Win8365790Test.java
index 5a690ea0146..62a648dce8e 100644
--- a/test/jdk/tools/jpackage/windows/Win8365790Test.java
+++ b/test/jdk/tools/jpackage/windows/Win8365790Test.java
@@ -23,6 +23,8 @@
 
 import static jdk.jpackage.test.HelloApp.configureAndExecute;
 
+import jdk.jpackage.test.WindowsHelper;
+
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -108,7 +110,7 @@ public class Win8365790Test {
 
         var future = CompletableFuture.runAsync(() -> {
             TKit.withState(() -> {
-                configureAndExecute(0, Executor.of("powershell", "-NonInteractive", "-NoLogo", "-NoProfile", "-ExecutionPolicy", "Unrestricted")
+                configureAndExecute(0, Executor.of(WindowsHelper.PowerShellPath(), "-NonInteractive", "-NoLogo", "-NoProfile", "-ExecutionPolicy", "Unrestricted")
                         .addArgument("-File").addArgument(TEST_PS1)
                         .addArguments("-TimeoutSeconds", Long.toString(Duration.ofSeconds(5).getSeconds()))
                         .addArgument("-Executable").addArgument(cmd.appLauncherPath(launcherName))
diff --git a/test/lib/jdk/test/lib/util/FileUtils.java b/test/lib/jdk/test/lib/util/FileUtils.java
index 3e537835c0b..8c149f3de81 100644
--- a/test/lib/jdk/test/lib/util/FileUtils.java
+++ b/test/lib/jdk/test/lib/util/FileUtils.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -475,4 +475,11 @@ public final class FileUtils {
             {"/sbin/lsof", "-p"},
             {"/usr/local/bin/lsof", "-p"},
     };
+
+    public static String powerShellPath() {
+        String systemRoot = System.getenv("SystemRoot");
+        String suffix = "\\System32\\WindowsPowerShell\\v1.0\\powershell.exe";
+        String fullPath = systemRoot == null ? null : systemRoot + suffix;
+        return (fullPath != null && Files.exists(Path.of(fullPath))) ? fullPath : "powershell";
+    }
 }