1) I am confused - are you trying to do a usb flash with Pure2 which will remove any other image
Or
2) are you trying to flash a slot in which case you should be using ImageManager
Either way PurE2 image for H7 needs a usb flash and as they change the slot size, you will certainly have only a PurE2 image installed.
Not sure what you expect to get out of running PurE2 apart from a different Image.