Registry value to check Logon Status of Citrix Xenapp 6.5 server

The logon's status is a combination of two keys, not just the one.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\TSServerDrainMode

AND

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\WinStationsDisabled

WinStationsDisabled =0 and TSServerDrainMode =0

Allow Logon and Reconnection (Allow all connections)

WinStationsDisabled =0 and TSServerDrainMode =1

Prohibit Logon until Restart (Allow reconnections, but prevent new logon until reboot)

WinStationsDisabled =0 and TSServerDrainMode =2

Prohibit Logon (Allow reconnections, but prevent new logon )

WinStationsDisabled =1 and TSServerDrainMode =0

Prohibit Logon and Reconnection