How to troubleshoot problems that may occur when you install, uninstall, or upgrade a program on a Windows-based computer
When you install, uninstall, or update a program on a Windows-based computer, you may receive one of the following error messages:
Error message 1
The Windows Installer Service could not be accessed.
Error message 2
Windows Installer Service couldn’t be started.
Error message 3
Could not start the Windows Installer service on Local Computer. Error 5: Access is denied.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB2438651.