Unfortunately, I made EEG recordings without a configuration file, I have data but I don't know which electrodes they correspond to. I would like to transform them and recover them in the configuration file format "10-20system64+8" because all my other data are in this configuration format (knowing that I can't open my .bdf files with biosemi with the error message "The file is not a valid LabVIEW file".
The BDF file recorded with default.cfg should be fully OK, but with A1...B32 labeling instead of the 1020 labels. The conversion between the two label styles for 64 channels is shown in https://www.biosemi.com/pics/cap_64_layout_medium.jpg .
The prevent the mistake in the future, you could consider renaming the 1020 cfg to default.cfg (ActiView starts up with default.cfg)