Top 7 Ways to Fix Windows Installer Service Could Not Be Accessed Error

Windows supports both official apps and third-party apps and software. Microsoft Store came into existence much later. But many users face the ‘Windows Installer Service Could Not Be Accessed’ error while running the installer file of a program.

The main reasons for this error include missing administrator rights, misconfigured or corrupt Windows Installer service, and system file corruption. We will discuss seven methods to resolve the issue and complete the installation.

1. Terminate and Restart Installer File With Admin Privileges

Before moving on to advanced fixes, close the installer program and run it with administrator privileges. Here’s how to do it:

Step 1: Press Ctrl + Shift + Esc keyboard shortcut to open the Task Manager. Find the app installer name and right-click on it. Select the End Task option.

Step 2: Press the Windows + E keyboard shortcut to open the File Explorer. Navigate to the installer file location and right-click on it.

Step 3: Select the Run as administrator option from the context menu.

Step 4: The User Account Control window will launch. Click on the Yes button to continue.

Step 5: Check if the app installation completes without the Windows Installer error.

2. Restart Your PC

The Fast Startup feature hibernates Windows system and kernel-level process and helps boot the OS faster. But if these processes glitch, you will keep facing issues with Windows features until you perform a complete restart.

Press the Alt + F4 keyboard shortcut to launch the Shut Down Windows utility. Select the Restart option and press Enter. Wait for your PC to power back on, then reattempt the app installation to check if you face the same issue.

3. Check Windows Installer Service

If the Windows Installer service glitches and stops working on your Windows PC, you will face trouble installing any program. To fix this, you need to restart the service. Repeat the following steps:

Step 1: Press the Windows key to open the Start menu, type services in the search bar, and press Enter.

Step 2: Scroll down and locate the Windows Installer service. Right-click on it and select the Restart option.

Step 3: Close the Services utility.

4. Reset the Windows Installer Service

If restarting the service doesn’t do the trick, you can reset the program. There is no option in the Settings app to reset the service, so you must do it manually using a registry file. But before that, manually back up your registry and export it on a USB drive. Here’s how to do it:

Step 1: Press the Windows key to open the Start menu, type Notepad, and press Enter.

Step 2: Paste the following code in the Notepad file:

Windows Registry Editor Version 5.00 [Computer\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

Step 3: Press Ctrl + Shift + S keyboard shortcut to open the Save As window. Name the file ResetWI.reg.

Step 4: Select the Save as type option and click on All Files. Then click on the Save button.

Step 5: Visit the location where you saved the registry file and double-click on it. The User Account Control window will launch. Click on the Yes button.

Step 6: Click on the Yes button.

Step 7: Lastly, click on the OK button.

5. Re-Register Windows Installer

If you are facing installation issues even after modifying the registry, you must re-register the Windows Installer using the Command Prompt. Here’s how to do it:

Step 1: Press the Windows key to open the Start menu, type CMD in the search bar, and press Ctrl + Shift + Enter keyboard shortcut.

Step 2: The User Account Control window will launch. Click on the Yes button.

Step 3: Type and execute the following commands one by one:

%windir%\system32\msiexec.exe /unregister
%windir%\system32\msiexec.exe /regserver
%windir%\syswow64\msiexec.exe /unregister
%windir%\syswow64\msiexec.exe /regserver

Step 4: You won’t see any messages after executing each command. Close the Command Prompt window and restart your PC.

6. Uninstall the Old Version of the Program

If you are trying to install a new program version that already exists on your PC, you need to first remove it entirely and re-run the installation. Here’s how to do it:

Step 1: Right-click on the Start button to open the Power User menu. Click on the Installed apps option.

Step 2: Locate the old version of the program in the list of installed programs. Click on the three horizontal dots menu and select the Uninstall option.

Step 3: Click on the Uninstall option again. Wait for Windows to remove the program from your PC.

Step 4: Restart your PC and then run the latest version of the program installer file with admin privileges. Check if you face the ‘keep waiting for installer service’ error.

7. Use SFC and DISM Scan

If all the above methods fail to resolve your issue, it points to a deeper problem. The core system files, including the Windows installer service, could be missing or the Windows Component store could be damaged. So, you need to run the SFC and DISM scans on your PC to replace missing files and service the Windows image. Here’s how to do it:

Step 1: Press the Windows key to open the Start menu, type CMD in the search bar, and press Ctrl + Shift + Enter keyboard shortcut at once.

Step 2: The User Account Control window will launch. Click on the Yes button.

Step 3: Type the following command and press Enter:

sfc /scannow

Step 4: After the SFC scan completes, type cls and press Enter to clear the terminal.

Step 5: Type the following commands and execute them one after another:

DISM /Online /Cleanup-Image /CheckHealth
DISM /Online /Cleanup-Image /ScanHealth
DISM /Online /Cleanup-Image /RestoreHealth

Step 6: Wait for the DISM scan to complete. Close the Command Prompt window.

Install Your Favorite Program

These were the seven ways to fix the ‘Windows installer service could not be accessed’ error. Start by granting administrator privileges to the installer file and check the Windows Installer service status. After that, modify the registry and re-register the Windows Installer using Command Prompt. Lastly, remove the old versions of the program.