try this code
Sub MakeNRed()
'
' MakeNRed Macro
Cells.Find(What:="n", After:=ActiveCell, LookIn:=xlFormulas, LookAt:= _
xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, MatchCase:=False) _
.Activate
With Selection.Interior
.ColorIndex = 3
.Pattern = xlSolid
End With
stophere = ActiveCell.Address
Restart:
i = 0
For i = 1 To 9999
Cells.FindNext(After:=ActiveCell).Activate
With Selection.Interior
.ColorIndex = 3
.Pattern = xlSolid
End With
If ActiveCell.Address = stophere Then GoTo TheEnd:
Next i
If i > 9999 Then GoTo Restart:
TheEnd:
End Sub
It should work fine