During installation, if you receive the following error message:

"The Windows Installer Service could not be accessed".

This can occur if you are running Windows in safe mode, or if the Windows Installer is not correctly installed.
Contact your support personnel for assistance.

It means your Windows installer has not been properly registered.
Any attempt to install any applications that rely on this service will fail.

To correct, follow these steps:

1. Click  START  in the bottom left hand corner of your desktop then click "Run".

2. Type "cmd.exe" without using the quotes. A MS-DOS command prompt will launch.

3. Type msiexec /unregister and press Enter.

4. Type msiexec /regserver and press Enter.

NOTE: See The Windows Installer Service Could Not Be Accessed Error Message When You Try to Install Office.
NOTE: See Overview of the Windows Installer Technology.

NOTE: See MSDN's Overview of Windows Installer.