EB installs within RTW folder in its own seperate folder. You get better A.I. if you use the BI .exe, and you can find out how to do that by searching the forums. Either way, If you have EB installed, you should not have difficulty playing Vanilla BI. I actually have EB and a mod for BI known as IBFD both installed, and I could (if I wanted to) play the vanilla games even with the mods installed, because the mods are installed in their own folders.