While installing some files on Windows, you might see an error message that reads, "This installation is forbidden by system policy."

Is this error appearing on someone else's device? If so, you need to ask for permission before proceeding with these tips. That's because some users disable installations to protect their devices from security threats.

Is the error message popping up on your own Windows device? If so, chances are that you've configured some settings unknowingly. Otherwise, the issue is caused by some bugs on your device.

Now, here's how you can tackle this "installation" issue on Windows.

1. Enable the Windows Installer Service

You'll likely run into various installation issues if the Windows Installer is disabled. In fact, you could even struggle to remove apps from your PC if this tool is disabled.

So, you could resolve the "installation is forbidden by system policy" issue by ensuring that the Windows Installer is enabled. Here are the steps you need to follow:

  1. Press Win + R to open the Run command dialog box.
  2. Type services.msc and press Enter to open the Services window.
  3. Scroll down and double-click the Windows Installer option.
Double-clicking on the Windows Installer option

Next, click the Windows Installer Startup type dropdown menu and select Manual. From there, press the Start button to enable the service. Finally, click Apply and then click OK to save these changes.

2. Configure Settings in the Local Group Policy Editor

You can also use the Local Group Policy Editor (LGPE) to tackle this issue. However, this method will only be useful if you use Windows Pro, Enterprise, and Education editions.

If you're using Windows Home, you can check out some tips on how to run the LGPE on Windows Home.

Now, here's how you can fix the "installation is forbidden by system policy" error using the LGPE:

  1. Type Edit group policy in the Start Menu search bar and then select the Best match.
  2. Navigate to Computer Configuration > Administrative Templates > Windows Components > Windows Installer.
  3. Double-click on the Prohibit non-administrators from applying vendor signed updates option on the right-hand side pane.
Configuring Windows Installer Settings in the Local Group Policy Editor

Select Disabled or Not Configured in the top-left corner. Finally, press Apply and then press OK to save these changes.

From there, apply the same settings to the Prohibit User Installs and the Prohibit removal of updates option on the LGPE.

3. Use Microsoft's Program Install and Uninstall Troubleshooter

The Microsoft Program Install and Uninstall Troubleshooter could also help—especially if corrupted Registry keys cause the issue at hand.

So, here are the steps for running this tool:

  1. Download the Program Install and Uninstall Troubleshooter on the Microsoft website.
  2. Double-click on the installed file to run it.
  3. Click the Next button and then select the Installing option.
Running the Microsoft Program Install and Uninstall Troubleshooter

From there, select the problematic app and then click Next. If you can't find the faulty app on the list, click the Not listed option and manually search for the program. From there, follow the on-screen steps to finalize the process.

4. Install Your Apps in Safe Mode

Installing your apps in safe mode could also help tackle the "installation is forbidden by system policy" error. This method could be helpful if faulty software programs cause the error.

Here are the steps for installing apps in safe mode:

  1. Type Settings in the Start Menu search bar and select the Best match.
  2. Select Update and Security and then click the Recovery option.
  3. Click the Restart Now button below the Advanced Startup option. Your PC will restart in the Recovery Environment.
Installing Programs in Safe Mode

On the next screen, click the Advanced options and select the Startup Settings. Finally, press the Restart button and click the F4 key to boot your PC into Safe Mode.

If you no longer run into the error, it's safe to say that a faulty software program or a device driver is causing the issue.

5. Isolate Faulty Programs by Performing a Clean Boot

An illustration of someone configuring settings on a PC

If you suspect some faulty programs cause the issue, you can perform a clean boot. This method helps isolate the programs that may be causing this error and other system issues.

The device boots up with all third-party applications disabled when you perform a clean boot. Also, the clean boot feature ensures that only a few critical drivers are running when you start the device. So, this process ensures that there are no interruptions when you install or uninstall software programs.

If faulty drivers cause the issue, you simply need to update or re-install those drivers. Otherwise, if a faulty app causes the problem, you can remove it and its residual files using a third-party uninstaller.

6. Re-Register the Windows Installer Service

Re-registering the Windows Installer service might sometimes turn out to be the best solution. So, here are the steps for re-registering this tool:

  1. Type Command Prompt in the Start Menu search bar. Next, right-click on the Best match result and select Run as administrator.
  2. From there, type the following command and press Enter to temporarily "unregister" the Windows Installer:

msiexec /unreg

When this process is complete, type the following command and press Enter to re-register the Windows Installer:

msiexec /regserver

Wait for the process to complete, and then restart your device to save these changes.

7. Configure Settings in the Registry Editor

Computer screen showing settings

As a last resort, you could resolve this issue by configuring a few settings in the Registry Editor. However, be sure to back up the Registry first before you proceed.

Now, here's how you can tackle the issue at hand using the Registry Editor:

  1. Type Registry Editor in the Start Menu search bar and select the Best match.
  2. Type Regedit and then press OK to open the Registry Editor.
  3. Navigate to Computer > HKEY_LOCAL_MACHINE > Software > Policies > Microsoft > Windows > Installer.
  4. Double-click on the DisableMSI value on the right-hand side pane.
Clicking the DisableMSI value on the Registry Editor

Set the Value data to 0 (zero) and then press OK. Close the Registry Editor and then restart your device to save these changes.

Install Apps on Windows Without Any Limitations

Windows installation errors can be pretty frustrating. Just when you're about to download a cool app, you come across error messages such as "This installation is forbidden by system policy."

The good news is that you can solve most installation issues with the Microsoft Program Install and Uninstall Troubleshooter. Otherwise, the other solutions we've covered should help you tackle the issue at hand.