Tried to get around a firewall for a windows remote desktop, changed the port number through registry, logged out, could not log back in. Was not able to change

Tried to get around a firewall for a windows remote desktop, changed the port number through registry, logged out, could not log back in. Was not able to change it either, detached the AWS volume, attached it to another device, could not access the registry to change the port back... I could see the screenshot, machine is running but couldn't remote in. Doing a recursive sudo chown of the /etc folder, locked myself out of that ubuntu server. Wrote a parser that had a condition that would not end, would watch the server spike to 100% usage.