How to kill a process in python 2.5 on windows 64bit platform?

I have a python script by which i am opening three executable files as follows:

Aa=subprocess.Popen([r"..\location\learning\A.exe"])
Bb=subprocess.Popen([r"..\location\learning\new\B.bat"])
Cc=subprocess.Popen([r"..\location\learning\new\B.bat"])

All the three files are getting opened. Now,next step i want kill these three opened modules.So, firstly i tried to kill "Aa" as follows:

PROCESS_TERMINATE= 1
k = ctypes.windll.kernel32klll
handle = k.OpenProcess(PROCESS_TERMINATE, False,Aa.pid)
k.TerminateProcess(handle, -1)
k.CloseHandle(handle)

But after adding these piece of lines the three modules 'Aa','Bb' and 'Cc' they don't gets opened.So,i want to know some clean solution so that firstly all the three modules gets executed and then after a while they get closed itself. As,i am using python 2.5 on windows 64 bit platform so kindly suggest solution accordingly.