Hidden Files and Access

Hello

I recently installed Vista and was trying to manually make a backup of my Outlook mailbox (outlook.pst). It is in a hidden file in the folder Documents and Settings. In order to see the file I had to change the settings making hidden directories visible, but I was unable to get into the directory (even though I now could see it). I don't understand this as I have Adminstrator priviledges and these are set to full privileges. Theoretically I should be able to get in there and view the file and copy it. Can anyone out there tell me what the heck is going on? Everything else seems to be fine, so I doubt there is some major issue.

Many thanks.

Dave