I tell you what...that's some attitude you got there for someone's who's asking for free technical support. We are sorry if we could not come up with you're "magic" answer...but simply, the symptoms that you have described defy the "laws" of normal computer operation. You asked for a solution, and the "computer guys" gave you a solution...buy a USB flash drive. But noooooo....you want to still use your floppies....and be free to leave them in computers when your absent minded ass forgets them. To answer your "OP"...there is no extra way to modify the boot sector of a floppy to inform the BIOS that it is not a bootable disk. There..you have your answer.