Help with dual boot

Hi:

I have two hard drives, and the XP installation on one of the drives
crashed. I tried everything I could to salvage it, but eventually gave
up and reinstalled on another disk. (Drive H). But even though one of
the installations doesn't work I still get a dual boot situation, and
can't access my personal files on the other drive. In general I'm not
too concerned about my personal files, because most of the stuff that's
important was duplicated in a portable folder on a thumb drive. But I
would like to reclaim the disk with the original boot so I can use it
for something else, and would like to get rid of the dual boot situation.

First, is there an easy way to modify the dual boot config and at least
set it up so that it autoboots to the installation that actually works?
Second, is there a way to ultimately delete the installation that
doesn't work, and get rid of the dual boot and reformat that drive?
Finally, is there any way to reclaim those files that I can't access
because of personal security before reformatting, or are those lost?