You can do that with a macro, if it is the same sheets then you can record a
macro while you unhide
them and then next time run that macro.. Or you can use what I use
Sub UnhideSheet()
Application.ScreenUpdating = False
Dim mySht As Worksheet
For Each mySht In ActiveWorkbook.Worksheets
mySht.Visible = True
Next mySht
Application.ScreenUpdating = True
End Sub