You may need to take ownership of the file or directory to gain access to the files,
http://support.microsoft.com/default...308421&sd=tech

As far as the boot problem, it sounds like you formatted the second hard drive and installed xp on it. Since xp takes around 2-4 gigs I recommend that you disconnect the second drive (one with 30 gigs missing)
Now do whatever you can to get xp running on your master drive. now hook up the slave drive and be sure to boot to the master xp. now get a disaster recover kit.

I recommend "GetDataBack - NTFS
http://www.runtime.org/gdb.htm

it will scan the second drive and show you the files it can recover for you.

Save these files to the master hard drive so you do not write over the data on the second drive.

Good luck!