Besides the obvious error with MessageBox vice MsgBox, this version worked
for me:

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$A$1" And Target 100 Then
MsgBox ("Changed Value")
End If
End Sub

Perhaps you have disabled events.

--
Regards,
Tom Ogilvy


"ExcelMonkey" wrote:

I have a simple change event in Sheet1. Why is this not firing when I type a
number greater than 100 in A1

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$A$1" And Target 100 Then
MessageBox ("Changed Value")
End If
End Sub

Thanks