Three things…

  1. Manual entry of workgroup (non-domain) machines on the management server seems to work: as long as you only use the Windows computer name (no domain suffix) for the computer name. I’ve used uppercase for the ID, and lowercase for the DNS entry; it might be case-sensitive.

  2. The non-domain systems need to be set to use a non-domain IP/hostname to use for contacting the management server (change made in Settings->Troubleshooting->Admin Console).

  3. An unexpected bug: one of my non-domain XP systems has an underscore in its computer name, but the management server won’t allow underscore DNS entries.

this is already known

I don’t know if the newest relase fix this issue, but what version of ABP console are you running?

Version 1.1.131.7

And I should also have noted that you may need to restart the Avast service on the client to get it to connect.