When using VS 2008 for testing, it will start Cassini at a specific port such as 8000. But sometime the port is in use. When try to start a web project, you will get message as :

Unable to launch the ASP.NET Development Server because port '8000' is in use.

How to release the port for Cassini?

(One way is reboot the whole computer, but that is not what I am looking for for many reasons)

Restart only the Cassini.

Right click--> Stop. 

 Thanks. But actually there is no any instance of Cassini started at the time. That is why I am confused.

Is there is anyway to find out which process is using the spefific port?

use this:

http://www.zdnetasia.com/techguide/windows/0,39044904,62047950,00.htm

 Great. Thanks.