The Windows Installer service could not be accessed' on Windows XP?
When you attempt to install a program that uses Windows Installer, such as Office XP, you receive:

"The Windows Installer service could not be accessed. This can occur if you are running in safe
mode or if the Windows Installer is not correctly installed. "
This error is probably the result of a damaged registration service.

To resolve this issue:

1. Open a CMD.EXE prompt.

2. Type msiexec /unregister and press Enter.

3. Type msiexec /regserver and press Enter.



that is it .. As frustrating as it was it should be fixed now