Ah, ok, i downloaded the 720kb-images from the download-section. I didn't knew that it's more common to use 840kb-disks.
OK, i tried one of the 800kb-images. The standard-loader in windows gives me an error, "Load error! Image file not supported!". But i can also load a raw image. s you can see it has much settings. How many sectors and tracks are used by the 800kb-images ? So i can try to import them with this raw loader.