Remote Desktop security settings

We have 2 XP machines that we use to program our phone system. The vendor set them up for my boss and I to remote connect; however, sometimes when we log off, we get this message: "The remote session to the remote computer was ended by means of an administrative tool. Your administrator might have ended your connection." Please understand that we do not get disconnected in the middle of a session, but this happens after we have logged off. Then we can't log back in because it thinks we're still logged in and says it's reached its limit of remote connections. I've gone through all the Local Security Settings and cannot find a setting that might be causing this.

The vendor's IT guy is no longer working for them, and the guy I usually talk to is a dufus, so I thought I'd try some gurus here. Any suggestions would be greatly appreciated.

Check this key on the computers

HKLM\Software\Microsoft\Windows
NT\CurrentVersion\WinLogOn\AutoAdminLogon

What is it set to?

That's not the issue then. Do you use the mstsc program to remote in or something else?

Have you checked the system logs on these 2 computers for any messages?

How often do these PCs get rebooted? Try rebooting them each night and see if you get the same errors.

You can send a remote reboot to the computers if you can reach them by network, check the "shutdown" command. You can reboot a remote computer using "shutdown -r".

Try installing VNC on the computers and remote in that way. Free remote connection software.