Another day, another strange problem. Thankfully, it did not take me a long time to figure it out. We have a Dell Precision T3400 workstation. Whenever we tried to connect to it using Remote Desktop, it freezes and the only way to get it back is to reset it.
I checked the logs and the only thing related to the problem is a log entry about TermService.
Event Type: Error Event Source: TermService Event Category: None Event ID: 1006 Date: 7/22/2009 Time: 10:54:23 AM User: N/A Computer: TEST Description: The terminal server received large number of incomplete connections. The system may be under attack. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. Data: 0000: 98 03 21 63 .!c
Before doing more diagnostics, I decided to do the regular maintenance first. I ran Windows Update and found that there is a newer version of the graphic card driver. BTW, this computer has a NVIDIA Quadro FX 570. After the graphic card driver was updated, I was able to use remote desktop client to connect to it again.
This case reminded me about a similar case. A computer I were working on got a BSOD after I disconnected the remote desktop session. The BSOD also indicated the offending component is part of the ATI graphic driver. So, if you have a problem with remote desktop connection, you might want to update the graphic card driver first.