Yes you can do this easily with the Windows API - basically you Enumerate through the processes and query the process for details like Window Name etc.. When you find the one you want then you can Terminate the process. This will all be invisibile to the OS Firewall, unless they Hook the Enumeration Functions, which I doubt. You don't need any special rights to do this.
PS. Google is your friend.
http://support.microsoft.com/kb/175030/EN-US/
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/terminateprocess.asp
PS. Google is your friend.
http://support.microsoft.com/kb/175030/EN-US/
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/terminateprocess.asp