DIY Fix Windows Installer Errors

Windows Installer errors are a fairly common problem on Windows-based systems that are often the result of damaged or missing Windows Installer files. When you try to install a Windows based software or application, you may receive an error message that is similar to the following error message: “The Windows Installer service could not be accessed.”

What is the Windows Installer?

As its name suggests, Windows Installer helps you install programs on computers running the Windows operating system. It can also facilitate the uninstall process when you want to get rid of a particular program. Windows Installer makes the installation process consistent across different programs, and is a standard part of any Windows operating system.

What are Windows Installer Errors?

A Windows Installer error happens when you are attempting to install a program and it fails to complete properly; you will be alerted to the error by a pop-up window. This type of error can be caused by a few different things. You may be running a program that is competing with the installer, you could be trying to install something while in safe mode, or the Windows Installer may not be properly installed itself.

How do I fix Windows Installer Errors?

If you receive a Windows Installer error, close all other programs and make sure your computer is not in safe mode. If this doesn’t correct the issue, Windows Installer errors can usually be fixed in just a few minutes using one of the following methods. If you are using a disc to install a program, you should also make sure the disc is devoid of any scratches or dirt.

Option 1: Enable Windows Installer

Perhaps the easiest solution to fixing a Windows Installer error is making sure that the installer is enabled. If you have disabled the program unwittingly, it won’t function when you are attempting to initiate the install or uninstall of another application.

    1. Click on the Windows Start icon and type “Run” (without quotation marks) into the search field.
    2. Click on the “Run” search result to bring up the “Run” box and then type “services.msc” into the text box. Click “OK.” The services window will open.


    1. Scroll down to the “Windows Installer” line in the services window and right-click. Select “Properties” from the drop-down menu that appears.


    1. Go to the “Startup type” menu and select either “Manual” or “Automatic.” As long as “Disabled” is not selected, Windows Installer is enabled. Click “OK” to save the new setting and then restart your computer to finalize the process.


Option 2: Re-register Windows Installer

Un-registering and then re-registering the Windows Installer application will give Windows Installer a fresh start, so to speak. If the program has become corrupted, this should resolve your errors by overwriting the bad files, and allow you to install or uninstall any programs without a problem.

    1. Go to the Windows Start icon and type “Run” into the search field.
    2. Click on the “Run” search result to bring up the “Run” box and then type “cmd” into the text box. Click “OK.”


    1. Type “msiexec/unregister” onto the command prompt screen where the curser appears and hit “Enter.”


    1. Reopen the “Run” box on your computer.
    2. Type “cmd” into the text box again and click “OK.” The command prompt screen will open again. Type “msiexec/regserver” into the window and hit “Enter.” While you won’t notice any difference on your computer, the Windows Installer will have been un-registered and then re-registered.


  1. Restart your computer to finalize the process.

Option 3: Run a virus scan

While somewhat less likely, a virus or malware issue can also be the cause of a Windows Installer error. Some viruses block programs from opening, including Windows Installer.

  1. Open your computer’s virus scanning program. If you don’t have one, a good free virus removal tool is [wpdm_file id=4]
  2. Initiate a complete scan of your computer. If any threats are detected, approve the quarantine and removal of the viruses.
  3. When the threats have been removed, restart your computer to complete the process.

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