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How to launch my C# application when any application starts in Windows 8?

I want to launch my application, like the windows security prompt, before any application is launched in Windows 8.
Is there any event handler, which gets notified whenever any application is launched?
My use Case : I want an App similar to a child lock(Lets call it myCustomApp).
When any user runs a game(say Solitare), i want myCustomApp to check the process name, and kill the process immediately.
P.S. : i am quite new to programming.
Thanks in advance!

Is there any event handler, which gets notified whenever any application is launched?
Yes: you get use WMI events to detect new instances of Win32_Process.
But these are created with process creation, not before.
Doing something between the call to ProcessCreate that creates the new process, and the process actually being created is going to be, at best hard (you might need to do it in the kernel), but quite possibly impossible.
Why do you want to do this? What problem are you trying to solve? This really does sound like an X-Y problem.
Edit:
The term you need to use is hook: the interception of some operation on windows. Eg. "Is it possible to hook the creation of windows globally so I can control where the windows are placed on the screen?"
There is a direct way in the kernel: PsSetCreateProcessNotifyRoutine
There are helpers in user mode (eg. EasyHook), but these require injected your code into each process (which anti-malware tools are likely to object to).
But you should still start out by looking for better approaches to you underlying problem.

Issue with the window focus in WinRT

I've got an issue with the focus management in WinRT. The issue is specific for the application startup. Let me share the example of it:
If during the startup I change the focus (for instance I can start selecting some text in a browser), the runtime will decide that it doesn't need to show the application. The application is being started in a 'hidden mode'. It means that I do not see the UI, but I still can find it in process explorer.
So what I need here is to make the application be active in all possible cases. I tried to use several native functions such as ShowWindow, SetActiveWindow, SetForegroundWindow, but without any success.
I also noticed that any WinRT app is being started under WWAHOST.exe and mainwindowhandle is 0. The app shows up if I use 'Switch to' option in Process Explorer context menu.

WinRT applications are sandboxed and have very little control on the way the OS handles them, and almost no way to affect the behavior of other applications running on the same host. What I would suggest then is for you to design your application in such a way that it shows some UI as early as possible, then asynchronously you can load any other resources that your application may need.

Unstoppable application in Windows

This question may be some times funny for all. Created an application in c# but my problem is in implementing that, the application should not be stopped in any case with out system restart. How can i do this? I heard about circular reference what is it and how can i apply it in my windows application
if it can be done using windows service then service can also be stopped from task manager but i don't want my application to stop

you can not do this, since the application can be closed using Task Manger. So the only way is to create two processes first represent your app second to check if your app is closed run it again.

You could create a service, as suggested in one comment. This will prevent people without administrative controls from stopping it. If people do have administrative control, they will be able to stop your program quite easily.
I checked for tricks kids use to go around Net Nanny. The most common trick is to install a virtual machine and use that for accessing the network. Users who aren't administrators can't install Virtual Box or the like, so the service solution will work against these, as well.

How can a Windows Service start a process when a Timer event is raised?

I have created a Windows Service with Timer and in firing event of timer.Elapsed I am creating a process (System.Diagnostics.Process.Start(exe path)) at interval of 5 seconds. But this process does not get created on the firing of an event.
Is there any other way of doing this?
Thanks in advance.
private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
Process pr = new Process();
pr.StartInfo.FileName = #"C:\Program Files\Messenger\msmsgs.exe";
pr.StartInfo.WindowStyle = ProcessWindowStyle.Normal;
pr.StartInfo.CreateNoWindow = false;
pr.Start();
}

You're adding descriptions of the problem in the comments as you go along that would have been helpful to know at the outset. The reason that you can see the process has started but no window ever gets opened is because of security model changes that were made to Windows Services under Windows Vista and later. You haven't mentioned it specifically yet, but I have a strong suspicion that you're trying to run this under one of those operating systems. The real issue is not starting a process, it's showing a UI.
What you're trying to accomplish is called an "Interactive Service", which is one that is allowed to interact directly with the user and the desktop (i.e., show a window or dialog).If you're using Windows XP (and your service will only ever have to run under Windows XP), you can follow the instructions in that article to enable your service to run in interactive mode, which will allow you to display the Adobe Acrobat application window as you expect. However, as that documentation also indicates, this feature does not work under Windows Vista and later:
Important Services cannot directly interact with a user as of Windows Vista.
Therefore, the techniques mentioned in the section titled Using an Interactive Service
should not be used in new code.
More specifically, in those versions, changes were made to how services and applications are run. Services are now isolated by the system in Session 0, while applications are run in other sessions. This is intended to isolate services from attacks that originate in application code. Hence, no UI shown by a service will ever be visible to any user on the system, including a simple message box. You can read the white paper that explains these changes in more detail here. If you're a more visual person, refer to following diagram illustrating the new model, paying specific attention to the dividing lines:
The upshot is that if you're targeting those versions, or might ever need to target those versions, you can't use this loophole. I say "loophole" because the bottom line, as I mentioned in a comment, is that Windows Services are not intended to be interactive. What you're trying to do here runs contrary to the purpose and design of a service. It wasn't recommended before, and now it flat doesn't work at all. If you need this particular functionality, you should create a different kind of application. Both Windows Forms and WPF are intended for user-mode applications, and both can start processes and open new windows as necessary. I strongly recommend that you convert to this style of application instead.

Since you won't get a process to show UI from the service, I recommend that you run the helper process when the user logs on and start your process from it.

I realize I'm a little late to this party. But since this question came up in my search for a solution, I'll provide an answer to the OP's question.
You can start a program from a service using CreateProcessAsUser, using the token of the logged-on user. MSDN provides a nice sample app demonstrating this; look for CSCreateProcessAsUserFromService:
https://code.msdn.microsoft.com/windowsapps/CSCreateProcessAsUserFromSe-b682134e#content
I tried it, and it works. I'm able to create a new process for my existing .NET application from a service, and it works just fine. I set the service Log On properties to Local System account, but left the "Allow service to interact with desktop" unchecked. My application is created when the timer expires, and works just like it does when started normally, including GUI presentation and user interaction.
Whether this is an improper or undesirable thing to do is another discussion. But it is indeed possible, and really not all that difficult.

There is a kind of work around, but i would advice to only do this if YOU ARE SURE TO ACCEPT THE SECURITY ISSUE!
This could be the Answer to your Problem:
CreateProcessAsUser.
The sample demonstrates how to create/launch a process interactively in the session of the logged-on user from a service application written in C#.Net.

Prevent application launch in C#

Okay I've spent the afternoon researching and haven't had much luck finding the answer to this. I am trying to prevent an application from launching via some sort of dll or background application. It is to be used in monitoring application usage and licenses at my institution. I have found leads here regarding WqlEventQuery and also FileSystemWatcher. Neither of these solutions appear to work for me because:
With WqlEventQuery I was only able to handle an event after the process was created. Using notepad as a test, notepad was visible and accessible to me before my logic closed it. I attempted to Suspend/Resume the thread (I know this is unsafe but I was testing/playing) but this just hung the window until my logic finished.
With FileSystemWatcher I was not able to get any events from launching a .exe, only creating, renaming and deleting files.
The goal here is to not let the application launch at all unless my logic allows it to launch. Is this possible? The next best solution I came up with was forcing some type of modal dialog which does not allow the user to interact with anything, once the dialog is closed the application is killed. My concern here is killing the application nicely and handling applications with high overhead when they load such as Photoshop or something. This would also interfere with a feature I was hoping to have where the user could enter a queue until a license is available. Is this my best route? Any other suggestions?
Thanks
edit: To clarify this is not a virus or anything malicious. It's not about preventing access to a blacklist or allowing access through a whitelist. The idea is to check a database on a case by case basis for certain applications and see if there is a license available for use. If there is, let the app launch, if not display a dialog letting the user know. We also will use this for monitoring and keeping track if we have enough licenses to meet demand, etc. An example of one of these apps is SPSS which have very expensive licenses but a very limited pool of people using it.

Could you use
System.Diagnostics.Process.GetProcessesByName
in a loop to look for the process?
It might work if you don't use too aggressive a polling rate.

You are indeed close, take a look at the WMI Management Events. http://msdn.microsoft.com/en-us/library/ms186151%28VS.80%29.aspx
Sample code from Microsoft: http://msdn.microsoft.com/en-us/library/ms257355(VS.80).aspx
Subscribing to the appropriate event will provide your application with the appropriate information to perform what you described.

Not sure if this is a GOOD solution but you could do something like pass a key into main so that if the key is not present or valid the application shuts down. Then when you open the application in your code, just pass the key in. Someone would then have to know the key in order to start the application.
This is assuming you have access to the application in question's source code, which upon reading your question again, I'm not so sure of.

I assume you don't have source for the application you want to prevent from loading...
Have you considered using a system policy? That would be the best-supported way to prevent a user from launching a program.
You could have a service running that force-kills any app that isn't "whitelisted", but I can't say how well that would work.

I wonder if you are taking the wrong approach. Back in the day there was a Mac app that would prevent access to the desktop and had buttons to launch a set list of applications.
IDEA
What if you had a wrapper for the approved apps then only allow your wrapper to run on the computer?

I would expect there is some way of hooking an application launch, but can't help directly on that front.
You may be able to improve your current approach by detecting the application's window opening and hiding it (move it offscreen) so that the user can't attempt to interact with it while you are trying to shut it down.
However, another approach that may be possible (depending on your circumstances) would be to write an application launcher. This simply is a replacement for the shortcut to the application that checks your licencing conditions, and then does a Process.Start to launch the real .exe at that point. This would work well for any application. (I used a system like this for starting up applications with specialised environment settings and it works beautifully)
You could combine this with your current approach as a fall-back for "clever" users who manage to circumvent your launcher.

If my understanding is right you want to create an application what will prevent the computer user to start any other process except ones for a white-list.
If this is the case, monitor the process list of processes (in a while loop) using System.Diagnostics.Process (the GetProcesses method gives the list of all running ones)
Just kill the process when it starts.
Or if your machines have Windows 7 (Windows 2008??) you can use AppLocker. http://www.microsoft.com/windows/enterprise/products/windows-7/features.aspx#applocker Just let Windows prevent the startup.

You might want to look at this product: http://www.sassafras.com/licensing.html Personally I can't stand it, but that's because it does what you describe. Might save you some coding.

You could actually edit the registry so when you click a psd, your launcher gets called instead of photoshop. Your launcher then checks for licenses and if there is one starts photoshop with the path of the file.

This is a long shot but you may find it helpful.
Perceived Types and Application Registration
http://msdn.microsoft.com/en-us/library/cc144150(VS.85).aspx