A: In order to run Feature Builder on either XP or Server 2003 you must create an environment variable named LocalAppData (set by default on Windows Vista and Windows 7).
How to Add LOCALAPPDATA variable in Windows XP
o Right-click on the My Computer icon and choose Properties
o Click Advanced
o Click Environment Variables
o Under User variables section, click New
o In the Variable name: field, type LOCALAPPDATA
o In the Variable value: field, type %USERPROFILE%\Local Settings\Application Data