diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 4e54f3ed6f..fb2a4e56c9 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -20,6 +20,7 @@ Release with new features and bugfixes:
 * https://github.com/devonfw/IDEasy/issues/1853[#1853]: Add ARM releases for VSCode on Mac
 * https://github.com/devonfw/IDEasy/issues/797[#797]: Use system unzip on macOS to preserve symlinks in ZIP extraction
 * https://github.com/devonfw/IDEasy/issues/1723[#1723]: Add commandlet for GitHub Copilot CLI
+* https://github.com/devonfw/IDEasy/issues/861[#861]: Fix install of pgadmin throws IllegalStateException when the install wizard starts
 * https://github.com/devonfw/IDEasy/issues/1685[#1685]: Add Nest CLI to IDEasy commandlets
 
 The full list of changes for this release can be found in https://github.com/devonfw/IDEasy/milestone/44?closed=1[milestone 2026.05.001].
diff --git a/cli/src/main/java/com/devonfw/tools/ide/tool/GlobalToolCommandlet.java b/cli/src/main/java/com/devonfw/tools/ide/tool/GlobalToolCommandlet.java
index 95c520a3b6..920c0eae48 100644
--- a/cli/src/main/java/com/devonfw/tools/ide/tool/GlobalToolCommandlet.java
+++ b/cli/src/main/java/com/devonfw/tools/ide/tool/GlobalToolCommandlet.java
@@ -159,7 +159,7 @@ protected ToolInstallation doInstall(ToolInstallRequest request) {
       executable = fileAccess.findFirst(downloadBinaryPath, Files::isExecutable, false);
     }
     ProcessContext pc = this.context.newProcess().errorHandling(ProcessErrorHandling.LOG_WARNING).executable(executable);
-    int exitCode = pc.run(ProcessMode.BACKGROUND).getExitCode();
+    int exitCode = pc.run(ProcessMode.BACKGROUND_SILENT).getExitCode();
     if (tmpDir != null) {
       fileAccess.delete(tmpDir);
     }
@@ -174,7 +174,8 @@ protected ToolInstallation doInstall(ToolInstallRequest request) {
     }
     installationPath = getInstallationPath(toolEdition.edition(), resolvedVersion);
     if (installationPath == null) {
-      LOG.warn("Could not find binary {} on PATH after installation.", getBinaryName());
+      throw new CliException("The tool " + this.tool + " is about to be installed. Please complete the installation and if required "
+          + "reboot your machine. Then rerun the command to start the tool.", 2);
     }
     return createToolInstallation(installationPath, resolvedVersion, true, pc, false);
   }
diff --git a/cli/src/main/java/com/devonfw/tools/ide/tool/pgadmin/PgAdmin.java b/cli/src/main/java/com/devonfw/tools/ide/tool/pgadmin/PgAdmin.java
index 46e1499497..9652701931 100644
--- a/cli/src/main/java/com/devonfw/tools/ide/tool/pgadmin/PgAdmin.java
+++ b/cli/src/main/java/com/devonfw/tools/ide/tool/pgadmin/PgAdmin.java
@@ -1,5 +1,8 @@
 package com.devonfw.tools.ide.tool.pgadmin;
 
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -7,6 +10,7 @@
 
 import com.devonfw.tools.ide.common.Tag;
 import com.devonfw.tools.ide.context.IdeContext;
+import com.devonfw.tools.ide.os.WindowsHelper;
 import com.devonfw.tools.ide.tool.GlobalToolCommandlet;
 import com.devonfw.tools.ide.tool.NativePackageManager;
 import com.devonfw.tools.ide.tool.PackageManagerCommand;
@@ -72,4 +76,30 @@ protected String getBinaryName() {
 
     return "pgadmin4";
   }
+
+  @Override
+  protected Path getInstallationPath(String edition, VersionIdentifier resolvedVersion) {
+    if (super.getInstallationPath(edition, resolvedVersion) == null) {
+      if (this.context.getSystemInfo().isWindows()) {
+        return getExecutableFolderFromWindowsRegistry();
+      }
+    }
+    return null;
+  }
+
+  private Path getExecutableFolderFromWindowsRegistry() {
+
+    WindowsHelper windowsHelper = WindowsHelper.get(this.context);
+    String registryPath = "HKCU\\Software\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\pgAdmin 4v9_is1";
+    String displayIcon = windowsHelper.getRegistryValue(registryPath, "DisplayIcon");
+    if (displayIcon != null) {
+      Path executablePath = Paths.get(displayIcon);
+      if (Files.isExecutable(executablePath)) {
+        Path installationDir = executablePath.getParent();
+        this.context.getPath().setPath(getName(), installationDir);
+        return installationDir;
+      }
+    }
+    return null;
+  }
 }