Stop executing exe using asp.net

Not sure if someone can help me on this. Really appreciate if you could.

I came across an asp.net code to execute an exe program in one of the forum the other day.

My question is, how can I stop executing an exe using asp.net. What I am trying to do is: Everything uses .net (either vb.net or C# will do). I will execute an exe program then I will keep track the time of its usage. Once the time reached certain amount, I will stop its execution and never allow the exe to be executed until after some time. I think I know how to execute it but how do I stop it and never allow it to be execute.

Thanks!!
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