For the latter, you may not want to reapply the registry backup, particularly if some time has passed; you would lose all the subsequent registry changes. But you, or a professional, can use the back up as a reference when selectively removing registry changes.
From an email I sent to a family member. Useful information.
The Windows AutoRun feature -- which automatically runs programs (desired or not) when you insert removable media, whether CD, DVD, USB drive, or similar -- is apparently difficult to disable thoroughly, from a conceptual perspective. This article describes how to do so. You have to decide whether you want to; however, for myself, I find the risk and/or annoyance outweighs the AutoRun convenience. For example, one time I inserted a music CD, to suddenly find the computer grinding away. Apparently, the CD had copy protection software that was trying to install itself. I'd forgotten to hold down the shift key while inserting, which is supposed to disable AutoRun on a case by case basis (this article doesn't discuss the Shift key feature, or whether it works in all cases; probably not, given that it describes how AutoRun can fire up not just on insert, but when you open something, even a directory, on the removable media).
If you have AutoRun disabled, you can always open up autorun.inf on the removable media to see what it would have run, e.g. what the set up program is on an installation disk.
Top Story, November 8, 2007
One quick trick prevents AutoRun attacks
By Scott Dunn