sproginator, which windows version are you running, as on xp pro sp3 in an administrator account I have no difficulties accessing & altering the folders needed, and assuming you are using administrator as your user name here is an xp path
C:\Documents and Settings\Administrator\Local Settings\Application Data\Ironclad Games\Sins of a Solar Empire
and for vista/w7 the path would be
C:\Users\Administrator\AppData\Local\Ironclad Games\Sins of a Solar Empire
regarding the ownership issue in vista/w7 if you right mouse click on the folder there should be an option to take ownership(possibly in the properties page or when you click into the folder).
hope this helps