Ok, I will be creating this tutorial pretty much all from memory.
First of all the Shell function lets you execute some of the commands you can execute in the Command Prompt (CMD).
Shell basically means it'll execute commands in a command prompt shell. Simple yet effective.
It's pretty simple, here's a quick example.
Private Sub Command1_Click()
Shell "cmd"
End Sub
What that does is it creates another cmd shell.
The great thing about the Shell command that you can easily use it to do stuff that would be pretty hard or complex in regular VB code.
In VB the code to kill or end a process, is really long, and complex.
Ok, so we know some information about the Shell command, and we know that it can make our programming experiance alot easier.
But, what are some downfalls?
Well, the thing about the Shell command is that it executes a command, and then quickly closes the cmd shell. So how can we fix this?
Simple... SendKeys.
Private Sub Command1_Click()
Shell "cmd"
SendKeys "ipconfig"
SendKeys "{enter}"
End Sub
That will start a cmd shell, and then it'll execcute the ipconfig command which will print information about your connection.
Now that code does work, but I don't suggest using it just how it is becuase it's a bit buggy. I know there are times where it'll open alot of cmd shell's and it won't execute the command.
If you want to do something like that, you might need to use the API but thats a bit to advanced for this tutorial.
Now, we know how the Shell command basically works. But to make sure we understand it, lets make some examples 
Private Sub Command1_Click()
Shell "Del C:\uselessfile.txt"
End Sub
That will delete the uselessfile.txt file off of the C:\ drive.
Private Sub Command1_Click()
Shell "TaskKill /f /im IEXPLORE.exe"
End Sub
That will kill Internet Explorer if it's running.
Ok, that looks good.
How about we start a program?
Private Sub Command1_Click()
Shell "Start C:\uselessfile.txt"
End Sub
Simple, that code starts up useless.txt in notepad 
Now, if you didn't know, you can start alot of programs through the cmd shell by simpley typing it's name like notepad, regedit, and some others.
Here are some more examples that some might find usefull.
Private Sub Command1_Click()
Shell "notepad" 'start notepad
End Sub
Private Sub Command2_Click()
Shell "control panel" 'open control panel
End Sub
Private Sub Command3_Click()
Shell "regedit" 'open up the registry editor
End Sub
Private Sub Command4_Click()
Shell "taskmgr" 'open up the task manager
End Sub
Well that will be all for now. I hope you enjoyed and learned something with this tutorial.
And please do rate it