How kill a process with the exe filename?

Hello, I need to kill a process before update it in C#, I can't use dzHW.dll coz I want get a one EXE file without dll file...
I searched for GetWindowThreadProcessId(IntPtr hwnd) and GetProcessById(Int32 id) but how get the process id? (PID) from an exe filename?
And how check if it's running? I tried with FindWindow but I need also the Windows Handle and I don't know the Window handle...

Anyone can help me?
Thanks for your replies!

Assuming you are on the desktop you can get an array of Process objects representing running processes with Process.GetProcesses or Process.GetProcessesByName for a specific exe. Once you have a Process object for the exe you can have your wicked way with it.

Yes I know how do it on Desktop but GetProcessByName doesn't exist on compact Framework... Is there an other way?

And with ToolHelp32? In dzHW library in VB I see some stuff with ToolHelp32 in VB but unable to understand how use it...

Thanks! Finaly a great response, each time I found only few informations but not enough... Thanks again I hope it'll works

I don't know how use it, how know the window name, window handle or process id?