Step by step
1). From Excel --Tools--Macro--Visual Basic Editor
2). From VBE --View--Project Explorer (if not already displayed)
3). Double Click "ThisWorkbook" Module
4). Paste the below

Option Explicit

' Change "Password" to a password of your choice
Private Sub Workbook_BeforeClose(Cancel As Boolean)
ThisWorkbook.Protect "Password", True, True
End Sub

Private Sub Workbook_Open()
Dim QueryUser As String

Const Password As String = "Password"

QueryUser = InputBox("Enter Password", Application.Name)

If QueryUser = Password Then
ThisWorkbook.Unprotect Password
Else
MsgBox "Sorry, No Workbook for you!", vbCritical, Application.Name
ThisWorkbook.Close SaveChanges:=False
End If

End Sub

"E" wrote:

I want to protect every sheet in a workbook with a password. I understand
this is tricky, so I will be satisfied if I can write a macro to password
protect every sheet, which will save me typing in the password twice for
every sheet.
I have used macros before by simply recording them, but have no idea how to
write the code myself. Please could someone give me some very simple
instructions how to write an appropriate macro, or edit one I can easily
record.

Thanks.