Problem:

Client was running an executable that was creating a file. Each time it ran it should have created a new filename - but it kept creating the same filename.

Resolution:

At one time they had an environment variable for the file name in the project properties under the application button.

The solution was to delete the rtecfg_....obj (most likely in working directory) and it take out of link properties in advanced "include objs"

Then the EXE was rebuilt

It's important that while testing environment variables that may change are only included in the IDE button and NOT the Application button. If they are included in the Application, the variable will be built into the executable.