Microsoft Security Essentials will not Install error code 0x004FF91.    After reloading windows  Home Premium I uninstalled Trend Micro, downloaded the Microsoft fixt it program MicrosoftFixit50535  and OneCareCleanup.    Still getting that same error code 0x004FF91.

I did veryify  that windows Installer service is running.

None of the tasks I see in task manager appear to me appear to  be antivirus or spyware.

Can anyone help?

(I selected "live mail" under product, did not see anthing in that list that was related to Microsoft Security Essentials)

Thanks in advance,

Dave