The windows installer service cannot update one or more protected windows files.

A quick tidbit for those that have come across this issue or may run in to this in the near future. I did a re-image today on a system and was boggled for a few minutes when I received the following error while trying to install Office 2007 Enterprise:

"The windows installer service cannot update one or more protected windows files."

hmm... ok let's try that again... Nope.. same error...

Ok time to take a look at the Event Viewer:

"Product: Microsoft Software Update for Web Folders (English) 12 -- Error 193 The Windows Installer service cannot update one or more protected Windows files. SFP Error: -536870654.
List of protected files: C:\program files\common files\microsoft shared\web server extensions\40\bin\fp4autl.dll"

Weird... After checking this directory there happened to be no such dll file.
Ok then... here's the Quick Fix:
download fp4autl.dll here

Then place it into the c:\program files\common files\microsoft shared\web server extensions\40\bin\ folder and then re-run the installation of office and you should be in business.

This has been a known issue since Office 2000 - you can check out the MS documentation here.