FS9 + Vista Screen Freeze Problem

Hello avsim community,I'm having some major issues with FS9 and vista all of a sudden. I recently reformatted my HD (yesterday) and today I reinstalled all of my programs and Vista again. I had been running vista and everything on the exact same setup prior to the reformat, I just wanted to clean my HD out and increase speed. Anyway not the point...The problem is when I open a flight in FS9 and try and do ANYTHING that involves changing the display (Shift-Z, S-key, Shift+1,2,3), the screen freezes. Something similar happened in my old installation of FS9 and vista however it was fixed if I minimized FS9 and then maximized it. This is however very annoying however it is all solved by running the program in full screen mode. All seems fine and dandy then except I have 5 years of FS-habits of flying in windowed mode and really want to fix my computer to make FS9 work in windowed mode. I normally use many windows at once while flying such as dispatch sheets, charts etc all open at once. I've tried everything from changing display settings, ensuring current drivers and downloading the newest directx.PLEASE HELP! Thanks so much!