I get an Automation Error when trying to change the password on a machine

Automation errors like,-2147467259 or -2147024843, indicate that the call to change the password failed. Many times this is because the system you are trying to change the password either does not support changing the password on it (Win9x), or is not a Windows PC (ie. a router, switch, unix/linux machine).
 
If it is a Windows PC that supports having it's password changed (NT 4.0 sp6a, Win2k, WinXP, Win2k3) then ensure that you have admin rights to the pc and nothing is blocking the call, (ie. firewall).