The msi.dll error is linked to the Windows Installer. Luckily, you can fix this error easily by reading the following information.

If you're receiving the error message “Error 1719. The Windows Installer Service could not be accessed. You may be running in safe mode or Windows Installer may not be correctly installed”, then you'll need to reregister your Windows Installer Service so that it may properly install the programs.

What is Windows Installer Msi.dll?

The Windows Installer Service is the process that manages downloads for Windows programs.

It is important that you do not remove msi.dll because that may negatively impact your system. Msi.dll keeps track of necessary files that programs use, and prevents deletion of shared files when you delete programs.

It keeps track of necessary files that downloaded programs need and makes sure that all necessary components are downloaded in order for the program to work properly.

Reregistering Windows Installer

While the msi.dll is a Windows system file, so should NOT be deleted, there is a way to prevent receiving this error message.

What you'll need to do is reregister the Windows Installer in the Windows registry.

o Close out of all programs

o Go to Start > Run

o Type in “msiexec /unregister” into the text field

o Open the Start > Run box again

o Type “misexec /regserver” into the text field

o Reboot

If you are still getting the error message, continue with these steps:

o Start > Run

o Type “msiexec /unregister”

o Go to “My Computer” and click “Search”

o Search for these files “msi.dll, msiexec.exe, and msihnd.dll”. Be sure you have “Search hidden files and folders” selected under “Advanced Options”

o Rename the files by replacing the “.dll” and “.exe” extensions with “.old”

o Windows will replace the renamed files from its dllcache

o Reboot and reinstall

If these don't work, try doing these steps while booted into Safe Mode

Organize your Registry and Delete Viruses

Viruses like to take on names of necessary Windows system and registry files. Be careful not to delete them manually, as there can be severe consequences if you delete the wrong file.

Double check to make sure your system file is not a virus by manually scanning it with antivirus software.

Also, make sure your registry is in top shape, clean, and organized by downloading a registry cleaner. A registry cleaner will fix msi.dll errors by scanning and replacing any corrupt files in your registry.

Source by John E. Blake