Take Ownership
HOW TO: Set, View, Change, or Remove File and Folder Permissions in Windows XP
http://support.microsoft.com/default.aspx?scid=kb;en-us;308418
HOW TO: Take Ownership of a File or Folder in Windows XP
http://support.microsoft.com/default.aspx?scid=kb;en-us;308421&sd=tech
Alternate method to take ownership:
Use the calcs.exe command line and reset the permissions.
The following comand line paramenter will change the ACLs of all files and directories on drive C to allow full control for the Administrators local group:
cacls c:\ /t /e /g Administrators:f