You are not alone if you are getting stuck at the “Windows installer service could not be accessed” while trying to install a program on your Windows system. Unfortunately, it’s one of the common errors of the most reliable and used OS.

The fact is, Windows throws this error mostly because of missing or damaged Windows installer files. However, outdated installer files could be the culprit.

Whatever the reason, there are some common troubleshooting methods to fix Windows installer service could not be accessed error.

Why Windows Installer Service Could Not Be Accessed Error Appears on Windows

Before jumping down into all troubleshooting methods, we should walk through why the error is appearing.

  • Damaged or missing Windows installer files.
  • Virus or malware-infected system.
  • Missing or damaged system files.
  • De-registered Windows installer.

Fix “Windows Installer Service Could Not Be Accessed” Error

Now that we know all possible causes of this error, we have shared all troubleshooting methods to fix the error.

1. Restart Windows

Whenever you face such an error in the Windows system, it is always recommended to start with a basic troubleshooting method before changing any settings within the system.

Therefore, you should restart the system first. It has been proven many times that restarting the system can fix many issues easily. Also, it improves the performance of the system as well.restart Windows PC

2. Ensure Windows Installer Services Enable

Windows installer service manages the installation and uninstall of an app. By default, the service is enabled. In case it is disabled by mistake. Here is what you need to follow to ensure the Windows installer service is enabled or not.

  1. Press Windows > type Run > Open it.
  2. Then type service.msc on the run window and hit the enter
  3. Scroll down and double-click on Windows Installer.
  4. From the General tab, click on the Start under Service status. It will enable Windows installer services.start windows installer

3. Start Windows Installer Service using CMD

CMD is an indispensable software to make changes within the system. Using CMD, we can start Windows installer service easily. Let’s follow this:

  1. Press Windows > search for Command Prompt > click on Run as administrator.Press the Windows key and type command prompt
  2. Now type the following command and hit enter.
     net start MSIServer
  3.  net start MSIServerAfter executing this method, Windows Installer will start.

4. Perform SFC & DISM Scan

As I stated, the “Windows Installer service could not be accessed” error came into existence because of corrupt or missing system files. Performing SFC and DISM scans can help to deal with corrupt files.

SFC Scan

  1. Open Command Prompt as Administartor priviliges.
  2. Then type the following command and hit the enter button.
    sfc /scannow
  3. sfc scanIt may take some time to finish the process.


  1. As usual, open CMD as administrator.
  2. Type the following command and hit the enter button.
    DISM /Online /Cleanup-Image /RestoreHealth
  3. Again, this also takes a few minutes to complete.

5. Uninstall the Older Version of the Particular App

If you already installed the older version of an app, getting a Windows installer error when installing the new version is common. Therefore, uninstalling the older version of the app could be helpful.

  1. Press the Windows Menu and click on Settings.
  2. Click on Apps > Installed apps.
  3. Now find the particular app, click on the three dots, and select on uninstall option
  4. Once successfully uninstall the app, restart the system.

6. Re-register the Windows Installer Service

Here is another steady method to fix when the Windows installer service is not working properly. Let’s make this change in your system:

  1. Open CMD as Administrator.
  2. Then type the following commands in the command prompt one after one, and each time wait for a few minutes to execute a command successfully.
    %windir%\system32\msiexec.exe /unregister
    %windir%\system32\msiexec.exe /regserver 
    %windir%\syswow64\msiexec.exe /unregister 
    %windir%\syswow64\msiexec.exe /regserver
  3. re-register the Windows Installer serviceThat’s how you can re-register the Windows Installer service to fix all issues within it.

7. Rename msiexec File

MSI or Microsoft Software Installer is used to install software on the target directory. So if the file exists without any extension, you should rename it. This is what you need to do:

  1. Open File Explorer, and navigate to C:\Windows\System32.
  2. Scroll down; you will get msiexec file; rename it to msiexec.old Rename msiexec File
  3. Now go to Windows Installer service, and start the service.

8. Reset the Windows Installer Service

When all these troubleshooting methods are not working for you, then resetting the Windows Installer service comes in handy.

  1. Press Windows > Search for Notepad > Open it.
  2. Now copy the following text, and paste it over Notepad.
    Windows Registry Editor Version 5.00 [HKLM\SYSTEM\CurrentControlSet\services\MSIServer] "DisplayName"="@%SystemRoot%system32msimsg.dll,-27" "ImagePath"=hex(2):25,00,73,00,79,00,73,00,74,00,65,00,6d,00,72,00,6f,00,6f,00, 74,00,25,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,6d, 00,73,00,69,00,65,00,78,00,65,00,63,00,20,00,2f,00,56,00,00,00 "Description"="@%SystemRoot%system32msimsg.dll,-32" "ObjectName"="LocalSystem" "ErrorControl"=dword:00000001 "Start"=dword:00000003 "Type"=dword:00000010 "DependOnService"=hex(7):72,00,70,00,63,00,73,00,73,00,00,00,00,00 "ServiceSidType"=dword:00000001 "RequiredPrivileges"=hex(7):53,00,65,00,54,00,63,00,62,00,50,00,72,00,69,00,76, 00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,43,00,72,00,65,00,61,00, 74,00,65,00,50,00,61,00,67,00,65,00,66,00,69,00,6c,00,65,00,50,00,72,00,69, 00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,4c,00,6f,00,63,00, 6b,00,4d,00,65,00,6d,00,6f,00,72,00,79,00,50,00,72,00,69,00,76,00,69,00,6c, 00,65,00,67,00,65,00,00,00,53,00,65,00,49,00,6e,00,63,00,72,00,65,00,61,00, 73,00,65,00,42,00,61,00,73,00,65,00,50,00,72,00,69,00,6f,00,72,00,69,00,74, 00,79,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00, 65,00,43,00,72,00,65,00,61,00,74,00,65,00,50,00,65,00,72,00,6d,00,61,00,6e, 00,65,00,6e,00,74,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00, 00,00,53,00,65,00,41,00,75,00,64,00,69,00,74,00,50,00,72,00,69,00,76,00,69, 00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,53,00,65,00,63,00,75,00,72,00, 69,00,74,00,79,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00, 00,53,00,65,00,43,00,68,00,61,00,6e,00,67,00,65,00,4e,00,6f,00,74,00,69,00, 66,00,79,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53, 00,65,00,50,00,72,00,6f,00,66,00,69,00,6c,00,65,00,53,00,69,00,6e,00,67,00, 6c,00,65,00,50,00,72,00,6f,00,63,00,65,00,73,00,73,00,50,00,72,00,69,00,76, 00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,49,00,6d,00,70,00,65,00, 72,00,73,00,6f,00,6e,00,61,00,74,00,65,00,50,00,72,00,69,00,76,00,69,00,6c, 00,65,00,67,00,65,00,00,00,53,00,65,00,43,00,72,00,65,00,61,00,74,00,65,00, 47,00,6c,00,6f,00,62,00,61,00,6c,00,50,00,72,00,69,00,76,00,69,00,6c,00,65, 00,67,00,65,00,00,00,53,00,65,00,41,00,73,00,73,00,69,00,67,00,6e,00,50,00, 72,00,69,00,6d,00,61,00,72,00,79,00,54,00,6f,00,6b,00,65,00,6e,00,50,00,72, 00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,52,00,65,00, 73,00,74,00,6f,00,72,00,65,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67, 00,65,00,00,00,53,00,65,00,49,00,6e,00,63,00,72,00,65,00,61,00,73,00,65,00, 51,00,75,00,6f,00,74,00,61,00,50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67, 00,65,00,00,00,53,00,65,00,53,00,68,00,75,00,74,00,64,00,6f,00,77,00,6e,00, 50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,54, 00,61,00,6b,00,65,00,4f,00,77,00,6e,00,65,00,72,00,73,00,68,00,69,00,70,00, 50,00,72,00,69,00,76,00,69,00,6c,00,65,00,67,00,65,00,00,00,53,00,65,00,4c, 00,6f,00,61,00,64,00,44,00,72,00,69,00,76,00,65,00,72,00,50,00,72,00,69,00, 76,00,69,00,6c,00,65,00,67,00,65,00,00,00,00,00 "FailureActions"=hex:84,03,00,00,00,00,00,00,00,00,00,00,03,00,00,00,14,00,00, 00,01,00,00,00,c0,d4,01,00,01,00,00,00,e0,93,04,00,00,00,00,00,00,00,00,00[HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesmsiserverEnum] "0"="RootLEGACY_MSISERVER000" "Count"=dword:00000001 "NextInstance"=dword:00000001
  3. Then save it using the Save as option from the File windows installer reset text on notepad
  4. Don’t forget to save the text file at the name repair.reg repair reg
  5. Open File Explorer, navigate to the saved file, and double-click on it.double click on repair.reg file
  6. Lastly, click on the Yes prompt to execute the change.

Final Words

That’s it – with these easy troubleshooting methods, you can fix Windows Installer could not be accessed error.

Moreover, don’t forget to update the latest to get compact performance and check for viruses and malware. However, if you have any questions or doubts, let us know in the comment section.