The Rename method is used to change the name of a computer either in a workgroup or a domain. When working remotely, the ...

The Rename method is used to change the name of a computer either in a workgroup or a domain.  When working remotely, the Rename method does not function for Windows XP Home Edition or on Professional Edition (workgroup only).  It should be noted that, for any computer in a domain (except the Domain Controller, since it can authenticate itself), delegation is required as a second hop is needed from the machine being remoted over to the Domain Controller for authentication.  There are no restrictions for local cases. 
If the Password and Username parameters are specified, then the connection to winmgmt must use a high authentication level (i.e. no less than RPC_C_AUTHN_LEVEL_PKT_PRIVACY) when they connect to winmgmt (i.e. in the call to obtain the IWbemServices interface) or SetProxyBlanket on their IWbemServices ptr. If they are local to winmgmt then this is not a concern because their authentication level is as good as RPC_C_AUTHN_LEVEL_PKT_PRIVACY as well as their client request never goes over the wire to get to the winmgmt. 
If Password and Username are left null, the provider does not care. 
If the provider determines that the authentication level is too low and a Password or Username has been specified then WBEM_E_ENCRYPTED_CONNECTION_REQUIRED will be returned. 
The method can return the following values:  
0 - Success. Reboot required. 
Other - For integer values other than those listed above, refer to Win32 error code documentation.