New Installations / Security - Owner Permissions

I have several hard drives in my machine. I generally find myself
reinstalling Vista or well, any other OS over the years about every six
months to have nice clean (as error free as possible) system running.

What I have always done is gone into each drive's route and taken ownership
of the contents of the drive. I believe that is the best way to actually
still own your data - ha ha. Now all drives are owned by the new
administrator(is that who I should set it to, or the 'user account with admin
priveliges'? Anyhow, after this task is complete I download a file to a
directory on one of the drives. I install the file, and then it mysteriously
just disappears.

Comments? Suggestions

Any help would be greatly appreciated. Thanks in advance for any help you
can provide!