A Comprehensive Guide To Fix Windows Installer Error

Clean Boot your PC

The Windows Installer program might have failed to access some of the important system components due to conflicts with third-party applications or services. Using the Clean Boot method, ensure only critical Windows services start at the system boot interval.

For Windows 10/ 8.1/ 8:

1. Right-click the Taskbar, select Task Manager if you’re using Windows 10, or Start Task Manager if you’re using Windows 8.1/ 8.
2. Click the Startup tab.
3. Turn off all Non-Microsoft startup items. (Right-click > Disable)
4. Restart your computer.

For Windows 7/ Vista:

1. Press Windows Key + R simultaneously, and hit ENTER.
2. Type MSCONFIG.
3. Press ENTER, or click OK.
4. Uncheck all the Non-Microsoft items that appear on your computer screen.
5. Click OK, and restart the PC when asked to confirm.

Temporarily Disable UAC

User Account Control, commonly abbreviated as UAC, is a security measure that prevents the execution of malicious code that can potentially harm your computer. It asks for user confirmation whenever an application tries to run code that can affect the way your computer works.

For Windows 10:

1. Press Windows Key + X; choose Control Panel from the menu options.

2. Open the following:

• User Accounts | User Accounts

3. Click on Change User Account Control settings.

4. In the subsequent dialog that comes, move the Slider to the extreme bottom.

5. Click OK to save your changes and reboot.

For Windows 8.1/ 8:

1. Press Windows Key + X, select Control Panel.
2. Click User Accounts and Family Safety | User Accounts.
3. Click on Change User Account Control settings.
4. Move the slider to the far bottom to select Never Notify.
5. Click OK.
6. Restart your PC.

For Windows 7:

1. Click Start.
2. Type Change user account control settings.
3. Open it from the Search Results.
4. Move the Slider to the extreme bottom, and click OK.

For Windows Vista:

1. Click Start, select Control Panel.

2. Type UAC in the Search Box.

3. Open Turn User Account Control (UAC) on or off

4. Uncheck the following checkbox:

• Use User Account Control (UAC) to help protect your computer

5. Click OK.

6. Now, restart your system.

Restart Office Source Engine

The Office Source Engine service must be running on your computer in order to install a software application with Windows Installer. Use the Services tool to determine if the service is already stopped, and re-start it again.

For Windows 10/ 8.1/ 8/ 7/ Vista:

1. Press the Windows Key + R.
2. Type services.msc and click OK.
3. In the Services tool that opens up, scroll down to locate the Office Source Engine service. If no service is found with this name, check for Office 64 Source Engine.
4. Right-click the service, and choose Properties.
5. Click the General tab > Start.
6. Set the Startup Type: Automatic.
7. Click Apply, and then OK.

Check Folder Permissions

If the Windows Installer encounters a problem accessing a specific file or folder, you might want to check it’s security settings and provide sufficient administrative privileges.

For Windows 10/ 8.1/ 8/ 7/ Vista:
1. Double-click This PC if you’re using Windows 10/ 8.1/ 8, or My Computer icon if you’re using earlier versions.
2. Open the directory that contains a file or folder that Windows Installer cannot access. You can find it in the Error Description itself.
3. Right-click the file or folder in question, and choose Properties.
4. Click the Security tab > Edit.
5. Check-up following items (under Allow column):

• Full control
• Modify
• Read & Execute
• Read
• Write

6. Click OK twice.

Reset Windows Installer Registry Settings

Some of the programs installed on your machine could have modified the System Registry in an incorrect manner. Restore the default Registry configurations as outlined in Method 1 of this Microsoft Support documentation.

Restart Windows Installer Service

For Windows 10/ 8.1/ 8/ 7/ Vista:

1. Open up the Services tool again.
2. Right-click the Windows Installer service, select Properties.
3. Click Start, if it’s already stopped.
4. Set the Startup Type: Automatic, and then click OK.

Delete Setup Extracted Contents

Windows Installer extracts installation files to a temporary location during the setup procedure. Files left-over after the previous installation may cause Windows Installer to function incorrectly.

For Windows 10/ 8.1/ 8/ 7/ Vista:
1. Double-click This PC or My Computer icon depending on your Windows version.
2. Open the following folder:

• C:\Windows\Temp\

3. Press Ctrl + A to select all files.

4. Delete all the files and sub-folders.

Reinstall Windows Installer

Reinstalling Windows Installer should automatically repair issues with its installation files, Registry entries and problems that prevent new programs from being installed. Here’s how:

For Windows 10/ 8.1/ 8/ 7/ Vista:

1. Press Windows Key + R.
2. Type RegEdit, click OK.
3. Locate the following sub-key:
   • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\
4. Right-click the msiserver sub-key, and choose Delete.
5. When you’re prompted to confirm, click Yes.
6. Fire up File Explorer, and open C:\Windows\System32
7. Delete the file named msiexec.exe
8. Visit Microsoft Download Center to download the latest version straight away.

Has Windows Installer Error Not Fixed Yet?

If the problem continues to appear, you might want to try error-specific solutions. Let us know in comments.