I dont think so. I always had problems with XSI (both retail, and mod tool) with Vista. Similar to what you are going through except mine was 64 bit. It wouldnt install right, and when it finally did install right the viewports would disappear after working with it for a while. It is strange because the exact same version i have installs, and works just fine in XP, and Windows 7. Sorry you are having trouble. Blame it on Vista.