Outlook 2007 archive.pst file permission issue. Access denied after migrating from XP to Windows 7.

I've recently preformed a clean install of Windows 7 Professional (32 bit) on my production desktop at work. In doing so I saved my archive.pst file from my user profile to a USB drive along with the other files that I needed on the new system. I installed Office 2007 Professional and activated the product. I had not added my user name to the local administrator's group when I moved the archive.pst to the new location (It was a long day and I regret that oversight now). I tried to open the data file with Outlook 2007 and received the following message:
 
File access is denied. You do not have the permission required to access the file C:\...\Outlook\archive.pst.

I have since added my user name to the local administrator's group, given my user name full rights to the C:\ drive and all subfolders, I checked the archive.pst file to be sure my user name had full permissions there as well. When I tried to take ownership of the file I received the following error message:

An error occured while applying security information to: C:\Documents and Settings\...\archive.pst
Access is denied.

Other details that might be useful for troubleshooting this issue:

The system is joined to our domain (Windows 2003 mixed functional level).
I am a member of the Domain Administrators group.
The Domain Admins group is also in local administrator group.
I have tried using Unlocker on the archive.pst file (Unlocker showed no security handles to remove)
I had to manually add permissions to many locations on the C:\ drive.