I have accidently deleted a workstation folder with 29 workstations in it - how do I get the machine registrating again.

I have cleared the ISD and chose NO to the question after you save the ISD and then re-imaged but this has left the devices agent saying its un-managed. I then checked the ISD and saw there was some info in it and then re-imaged again but still no registration.

I thought clearing the ISD would force it to make a new GUID and regester under this. What am I doing wrong. I cant seem to run a zac reg keeps coming back with "Registration Manager - Netowrk error connecting to server : The underling connection was closed. An unexpected error occurred on a send"

I`m sure I am using the right credentials (same one to login to ZCC) and use the line https://(serverIP):8080 as its on that port.