So I had a nasty surprise on my virtual machine this afternoon. Windows had decided to upgrade me to IE9 without asking. (In my settings, I generally have important updates set to automatic, but to ask me before installing any other updates.) A lot of my work involves manipulating what things look like and function like in the browser and, as such, I try to keep my virtual machines as close as I can to my clients' configurations. This was NOT good news.
Good news is you can uninstall IE9 if you want. Just go to Control Panel->System and Security->Windows Update->View installed updates and scroll down to IE9. Right click to uninstall. If you have (had) IE8 on the machine, it will go right back to it. Mine did without issues.
You can also prevent Windows Update from installing IE9 by downloading a Toolkit from Microsoft at http://www.microsoft.com/download/en/details.aspx?id=179.