Unchecking IE9 in Turn Windows Features On of Off will not uninstall IE9, it will only turn IE on or off.  You must follow my instructions to remove IE9 to leave IE8.  Windows 7 has, in its core code, IE8 integrated into the OS ... IE9 is only an update to it.   Reinstalling is always an option ... I'll tell you more if you need to.
I recently bought 2 systems. They are Windows 7 64 bit. They came with Internet Explorer 9 installed. One of our business' software will not work yet with IE9. (Not until sometime next year I have been told) I have been unable to find a IE8 installation that will work. All the ones that I've tried off of Microsoft's site give me an error and won't install. I bought a Windows 7 64 bit system a few months ago and that has IE8 so I know it is possible. Until I find a version that will install I have two useless PCs. Thanks
Windows 7 system needs IE8 