Sub DeleteRows()
'
With ActiveSheet
.AutoFilterMode = False ' Remove filter
.UsedRange.AutoFilter Field:=1, Criteria1:="<>x" ' Filter column A for not = "x or X"
.AutoFilter.Range.Offset(1).EntireRow.Delete ' Skip header row 1 & Delete the rest
.AutoFilterMode = False ' Remove filter which leaves remaining rows
End With
End Sub