The application is written in C, linking in the commode.obj modules I believe this is do to the “delayed cache write” behavior of windows, but need a work around. The scenario is as follows: Works: Program 1 starts Program 1 opens file A Program 1 close file A Program 1 exits Program 2 starts Program 2 opens file A Program 2 close file A Program 2 exits Fails: Program 1 starts Program 1 opens file A Program 1 close file A Program 2 starts Program 2 tries to file A ……. file busy error … enter a loop retry open every second Note Program 1 still running Now terminate program 1 Program 2 opens file A successfully Program 2 close file A Program 2 exits Now we have tried liberal doses of flush but they do not seem to have any affect. Suggestions? Regards Carl

Alternative 1 Try sopen. That will open for shared access. Alternative 2 Try mailslots for sending stuff between the programs Alternative 3 Try shared memory for sending stuff betwen the programs Alternative 4 Try pipes for sending stuff between the programs.

All good suggestions, but unfortunately not practical. I have many codes, on the order of 200, that called in optimization loops. I just really need to close and free a file completely from with a running program. Never thought that she be so hard…