Since Windows Vista was released, Windows has had a security feature called the Virtual Store. Some legacy applications will try and read/write configuration files in a location that would require administrative privledges (eg. C:\program files\<application>). The Virtual Store is used to allow these applications to continue to be able to read/write files in this location (virtually), but they get stored in the Virtual Store. They just appear to virtually be under their original location. This happens transparently to the application.
The location for the Virtual Store is as follows:
C:\Users\<username>\AppData\Local\VirtualStore
To easily access this location, paste the following path into the location/url bar in Windows Explorer:
%LOCALAPPDATA%\VirtualStore
This will automatically convert the %LOCALAPPDATA% variable into the local application data folder for the currently logged in user.
OR
C:\Users\%USERNAME%\AppData\Local\VirtualStore
This will automatically convert the %USERNAME% variable into the username of the currently logged in user.
For more information on the Virtual Store security system, you can visit http://msdn.microsoft.com/en-us/library/windows/desktop/bb756960.aspx