That's a mystery. "Subscript out of range" in this case means that it is not finding a file called "try.xls", so your problem lies there.
Only two things i can think of to see if you can narrow down why it's not working, one, try
Code:
Sub TryThis()
Workbooks("try.xls").Close
'instead of
'Application.Workbooks("try.xls").Close
End Sub
or try closing all workbooks, then open the workbook with the macro first, then open the "try.xls" workbook next, then try
Code:
Sub TryThis()
Workbooks(2).Close
End Sub
see if that makes any diff