The state of premium graphics applications UI, in not just AutoCAD, is such that the days of using a single monitor are coming to a close. If you are not on multiple screens you are doomed to continuously turning on and off floating bars, tabs, and windows.
This is not to deflect the criticism that Exchange should be user-resized as needed to whatever size required, that's a missing development that needs to be addressed (most likely will never happen in R2012).
To turn OFF the internal Acad Help browser, go to Tools, Options, System, and uncheck the "Access online content" box. You can check either default or IE, you'll get the local files. The online links won't show up on the right, but that's a small price to pay for getting that &@(#$* internal browser out of my face. And I can just click the bookmark any time to get here anyway, or to AUGI.