Change adjacent cell depending on text

OK, fixed it.

For future reference, this is what I used:

Sub acreps()
For Each rw In ActiveSheet.UsedRange.Rows
  If rw.Columns("C") = "XXXXXXX" Then
    rw.Columns("B") = "YYYYYYYY"
  End If
  If rw.Columns("C") = "XXXXXXXX" Then
    rw.Columns("B") = "YYYYYYYY"
  End If
Next rw


End Sub