"Cant Open....." and "...it opens..."
The function of the program is to load a disc image (ISO) to a USB stick and make it bootable.
It's just asking you what you want to make bootable.
Hello,
It sounds like the download is prompting you to select an ISO file and a save location. This could be due to your anti-virus (A/V) software interfering with the process. Try temporarily disabling your A/V software and attempt the download again. If the issue persists, make sure you have the correct permissions and enough space on your chosen drive.