First the following macro works when run from with in the "Data Base"
sheet.

But when I paste this code in Private Sub Worksheet_Activate() for the
Data Base sheet I get an error 1004 on the range("b2:d325).select

Why?

Sub Macro1()

ScreenUpdating = False

Sheets("Data Base").Select

Range("B2:D325").Select

Selection.Sort Key1:=Range("C2"), Order1:=xlAscending, Key2:=Range("B2")
_
, Order2:=xlAscending, Key3:=Range("D2"), Order3:
=xlAscending, Header:= _

xlGuess, OrderCustom:=1, MatchCase:=False, Orientation:=xlTopToBottom
Range("B2").Select

Sheets("First Name").Select

ScreenUpdating = True

End Sub