I had a missing hal.dll issue last year. Dont remember how i fixed it though (recovery console i think).
But searching hal.dll gets a lot of hits on google. See if you can find any useful information on solving the issue..
As for the MBR issue, thats probably a boot loader issue. The recovery console on the XP install disk will fix it. Just enter the command "FIXMBR" (without the quotes)
Bookmarks