Hi, I cannot connect from my Vista to another machine using the serial null modem cable. I also have an XP machine, and it can connect to the target machine without a problem. So it seems the Vista is the problem.My Vista machine does not have a modem. (My XP has one - do I need a modem installed for the null modem connection?)I wondered if it should be "Communications cable between two computers" and tried to add it. But it crashes my Vista. Then it keeps asking for the "Driver" each time the machine is rebooted up. I tried the OS and driver CDs but Vista cannot find the driver for "Communications cable between two computers".Does anyone have any similar experience?My machine is a Dell optiplex 755. Dell support was not helpful. (Seemed to suggest I need a modem.)Thanks.

Hi, Thank you for posting. After researching, I found the Windows Vista does not support this connection. Please see if you can use analternate method to connect the two computers together. Meanwhile, please refer to the following Knowledge Bases: You cannot use a serial cable connection to connect a Windows XP-based computer to a Windows Vista-based computer http://support.microsoft.com/kb/928354/en-us The option to use a serial cable connection or an infrared link is unavailable when you create an incoming connection in Windows Vista http://support.microsoft.com/kb/930086/en-us Hope this helps. Thanks.Nicholas Li - MSFT