Good work.
I wonder on the actions listed if the approach is a little too 'reactive' ?
Might it be better to take a step back and look at what occurred from a higher level, i.e. you installed something (MOM/SQL), and as a direct result it changed settings in something else (IIS).
Instead of watching for this specific fault occurring again, why not try and develop something that watches all settings perhaps in the registry?, and reports back on anything that could be deemed a bit unusual or suspicious? Like an advanced event viewer tied into the installation? or a seperate program, you could call it: MS Install Monitor V.1.0 .. heh.
ok, easier said than done i know .. but i'm wary that tomorrows problems will not be the same, so something that is analysing the system as a whole may point you to the problem area more quickly.
Similar i guess to the Vista journal that assists trouble shooting by recording all change and associated errors on a timeline. Except this would just be aimed at watching what on the system has changed during the course of an install and rolling up those changes into a summary with warnings of irregularities etc..
once again, good work all round :o)