Weird installation of IE9 RC in Windows 7

ie9-rc-aboutI have not seen before such a weird installation. So I was going to install newly released Internet Explorer 9 RC 32-bit (build 9.0.8080.16413) for Windows 7. So what happened after I hit the executable IE9-Windows7-x86-enu.exe—I was asked a permission to close a bunch of running programs: uTorrent, Skype, etc. I agreed. But IE9 installer closed not only those, but also stopped Microsoft Security Essentials (MSE was shouting like almost caught a virus) and … Explorer.exe. Which meant I had to stare at status window on the top of the wallpaper — nothing else (please see the screenshot below):