Not sure if this has been covered before if so please accept my apoligies.
I had a W7 system with ZA 90.007 working for a few months and all was well.
When W7 SP1 came out I tried to apply it and got a bricked system. Basically, nothing would run, and I mean nothing. Error message was '.. you do not have required permissions'
Was on to Microsoft etc, not solutions.
I had to re-install W7 from the DVD and then SP1 installed fine. Installing ZA 90.007 nuked my system with the same symptoms.
So basically you will need a complete system re-install if you install ZA 90.007 on a W7 SP1 machine. This is truely bad.