You have to consider what context the Altiris process is running in, and on what operating system you are running it.
Since the Altiris client is typically running using the LocalSystem account, any process spawned using this account will not have access to any network resources as the LocalSystem account does not have network rights. Therefore any copy task which needs to copy files from a network location to the local hard disk needs to be run using a domain account.
When it comes to importing registry keys, you need to specify whether the keys are intended for the HKLM hive or the HKCU hive. If HKCU, bear in mind that this will not be the user account that may be logged in, but it will be the service account that is updated. So for HKCU settings you need to identify the SID(s) of any user(s) logged in and target HKU\<sid> instead. If you use roaming profiles then you need to use something like active setup instead, as the user profile may not exist locally if the user is not logged in.