Windows XP's built-in firewall is primitive. Ensure your XP machine sits behind a robust hardware router/firewall.
To unlock the "full feature" set (remote control, file transfer, and clipboard sync) during a session, the remote (XP) machine must grant these permissions: Initiate Connection : Enter the XP machine's AnyDesk ID from your local device. Accept with Full Access anydesk windows xp
on setting up unattended access specifically for a server environment? Windows XP's built-in firewall is primitive