I needed to keep a Windows XP machine which I connected to using RDP connected all the time – until I logged off.
The default was set to log me off after 30 mins or so of inactivity which meant I had to go through the whole process of logging on again!
It appears the only way to achieve this is by editing some registry entries:
HKEY_LOCAL_MACHINESOFTWAREPoliciesMicrosoftWindows NTTerminal Services
Delete the MaxIdleTime key.
If MaxDisconnectTime key is also present then delete that as well.
Now my RDP connection stays connected as I wanted.