Vista Ultimate Bit Locker

I though that this had been posted a while back - anyway, I had files encrypted using Vista Ultimate Bit Locker onto external hard drives. They are still there. March last the computer refused to boot properly no matter what I did. Under warranty, a tech came to my home and inserted a new (500GB) hard drive. No luck. A second tech arrived later and inserted a new mother board (Acer Aspire E 700 with high end video card added). Tech decided that my second 120GB internal drive was the problem all along an unplugged it, reinserted my old drive (500GB) as the new second internal drive and reinstalled Vista Ultimate on the new C:\ drive. I think the problem of not being able to view my encrypted files is one of Administrator recognition (I live alone - only user !) but I have about 4 different Administrator names over time with accompanying documents etc. scattered through out the old and new drives. I think I can somehow restore the complete backup made before the (crash ?) to the OLD (now 2nd internal) drive and look at the files from there if I used a dual boot to install Vista Ultimate to the old drive (that was corrupted when attempting to reinstall Acer start up files). I used dual boot some years back with Windows XP but see no reference to the prodedure for Vista. Is their a simpler way to un-encrypt these files? I still have the password of course.