How to backup a disk from another PC

I have a disk that came from a dropped PC (Vista). Would like to back it up to ensure I've got it preserved, buy connecting it to another PC (also Vista). Running as admin, I'm getting told I can't access the other disk, unless I adjust the permissions on it to grant access to me (newPC\Admin). But even this seems to result in "access is denied" errors on the source disk. Is there a good way to backup the complete source disk using another working PC?

You probably need to Take Ownership: http://www.vistax64.com/tutorials/67717-take-ownership-file.html