To edit or create a button image
Customize
InterfaceAt the Command prompt, enter
cui. 
C:\Documents and Settings\<user profile name>\Application Data\Autodesk\<product name>\<release number>\<language>\Support\Icons
When saving a button image, the Button Editor defaults to the folder defined under Custom Icon Location on the Files tab of the Options dialog box. Button image files placed in the folder can be migrated with the Migrate Custom Settings dialog box in future releases.