That is the biggest problem with anything Windows — they change the defaults without any explanation.
It has taken me nearly 6 months to make Win7 usable — by changing those defaults to more practical use.
UAC was the biggest problem creator I had. It messed up many programs and their configurations. I finally turned it off completely, and normal returned to my pc world.
I may re-check IE9, however I only use IE occasionally anyway, so it is no big deal.
I have a completely opposite opinion. The strength of MSWindows is the ability to customize the interface to the user preferences and to the hardware being used. If you want zero ability to changes things and hardware with training wheels attached, there is another brand you can buy.