I got seduced into upgrading to IE-7 some years ago, and the initial version of it sucked pretty bad. I had a geeky friend who told me how you can cause your computer to revert to a date and time that was PRIOR to the date and time you downloaded the new version, and voila!...you are magically back where you originally were. No harm, no foul. (I do not remember how I did it, but one of our Freeper friends surely can). Anyhow, if-and-when they get the new version cleaned up to where it no longer sucks, THEN you can move on up to it.
You are talking about a system restore. Anyone can do it, although you need to know where to find the control to start it on your computer. Go to Google, then enter something like “system restore windows vista” and you should get plenty of references.