Hello, guys.
I got this #4444 error too under powerquest pq7 and pq8 but it's ok under norton pq8.
Also I installed Vista on my hd, and i also think this is the problem.
I fix this error just by running chkdsk under win xp twice,
if not done, put vista boot disc to CD-Drive, and switch to boot folder, run bootsect /nt52 C

or D: etc..) may give little help too.