Follow this instructions and you will have 100% success.
Go to visual studio and create
1.Label which will show the random number
2.Button which when it is pressed the random number appears to the label
3.Numeric up-down which you will give the biggest number that will be drawn.
When you create all these on the designer of the form double-click the button and paste the following code(visual basic code):
Label1.Text = CStr(Int(Rnd() * NumericUpDown.Value))
If you have any problem tell me