Vbs script, you can use it to prank your friends that they'll have to format their hard disk.

Error.vbs

result = MsgBox ("Error 73873a. Do you want to format the hard disc?", vbYesNo+vbCritical,"Critical Windows Error")

Dim message

Select Case result
Case vbYes
    result = MsgBox ("Are you crazy?", vbYesNo+vbCritical,"User")
    Select Case result
Case vbYes
    message = "Fortunately!"
Case vbNo
    message = "So why you're using computer?"
End Select
Case vbNo
  message = "You decided well."
End Select

MsgBox message, vbInformation,"User"