There are issues with file access on some windows machines when simulation file are being accessed by another application, including file manger. If that is happening, it is best to not have the run directory open in file manager, or any results files that will be overwritten open.

If you go to "About" under the "Help" menu there is a dialog box that has a "show detail" buttons. If you click on that, among other things ,it provides the name of the temporary directory the simulation was run in. You may find the files there.