Vlk
9
The problem is that the AMS machine already has a connection to the target – but with a different set of credentials. Windows doesn’t support connecting to a remote host with more than one set of credentials.
Do a net use command from a command prompt (on the AMS) to see if you have a mapping to that host. If so, either delete it (by using net use /d) or make sure the account specified in the avast deployment task is the same as you’re currently logged on.
I hope this makes sense to you. 
BTW is this NT4?
Vlk