Again, thank you for your help and your quick replies. Jian had suggested a way of changing all the QB files ending in .bas, to .QB, which I did, because QB.exe now shows .QB as the proper extension for its files. And, yes, double clicking DOES open the .QB files in QuickBASIC. Tha is O.K. It's only when I open QB.exe, then click on File, Open, that the *.bas still appears and, since all my QB files now have the extension .QB, no files are shown, until I change the *.bas to *.QB