How to fix security on external drives brought in from Windows XP

[Eric]

I'm a relatively advanced user, but this issue is really causing me grief.

I upgraded my computer from XP to Vista Professional and now I am really
sorry for doing it.
Both my C and D drives were present when the upgrade took place.

I have a D: drive which has my data on it. Some folders when I try to open
up files it tells me I don't have permission and I can't open files.

When I look at the owner of the files, it is me. When I look at the other
security attributes, it shows me as having full control.

If I use the "Take Ownership" option on each file one at a time, it succeeds
and I can open each file.

If I use the "Take Ownership" option and propogate the ownership through
files and folders, it doesn't work, and I cannot access the files, even
though the files will show that I own them.

I have close to 50,000 files on this drive and I can't justify myself
spending years doing each file once at a time.

Does anyone have any kind of fool proof method for wiping out secuurity
attributes and reapply them the Windows Vista Professional way?

--
Eric Levinson