Kind of depends on what you mean by copying the disk to a flash drive. If you're just directly copying the files, probably not although it could be possible.
Most likely, you'll want to make an optical disk image or .iso file (google "how to make an .iso file" if you don't know how to) then you'll want to copy the .iso file to the flash drive. From there you'll need to mount the image on your pc (google "how to mount an .iso file" if you need to). If I remember correctly, Windows 8 and above can mount .iso files natively, but otherwise you'll probably need some other software to do it.