Have you got the name "Fixed.xls" absolutely correct? If the sheet
does not exist you get the Run-time error  '9'; Subscript out of range
message.
Does Worksheet(1) exist? (I suppose it must) but to debug try
temporarily referring to it with its name instead of its index eg.:
x = Workbooks("Sheet1").Worksheets(1).Cells(i, 2).Value

The code  in your message doesn't activate Fixed.xls by the way, nor
does it need to, to work.