On Fri, 2011-02-25 at 06:29 -0600, slileo wrote: > No program writes to this file. It is a file with inputdata needed for the calculations that several programs (Windows compiled) have to read. > In that case I don't understand why the second program is getting blocked unless its M$ Fortran is imposing its own additional access controls or its running as a different user which doesn't have read access to the file. Martin