Open only one instance of Windows Calculator

Of course your question is clear to you because you understood it before you even wrote it. What I am saying is that it was not clear to us.

You said "on my web application" yet it is not clear to me whether the calculator is executing in the server or the client. Also, does your solution work even when there is an instance of the calculator program executing before your application executes it? If not then doing that will make the solution more complicated. Also, you said "opened a windows calculator" but you never were clear about what program.

Dear Sam and All,

Thanks but i solved it my self :-). My question was very clear that i have opened one instance of windows calculator and i don't want a user to open another instance of that calculator if he/she again clicks on the button :-).

Your question is confusing for us; it is definitely confusing for me.

I don't need to know why you are doing that except it might help me understand what you need to do. I don't understand why you need to limit the calculator accessory to just one instance. If there is a valid reason to do that then it could be done, but not easily and probably not using C#. I assume that you actually need to do this for a different program.

As Ashot implied, it is possible to do that if it is a program that you wrote or that you at east have the source code for. If you do, then there are many articles available that can help. If you do not, then please calrify what you need to do, in terms of why. I need to know why if it can help me understand what you need to do.

Dear Ashot,

Your answer is a bit confusing to me :-).

Thanks