As it says: "Insert system disk", you don't need my utility, as it'S already trying to execute the boot sector. My utility is just for Bootblock-versions which request to insert a disk with awdflash.exe so that you are able to boot normally.
Are you sure, you created a correct bootdisk with a sane boot sector?
if in doubt, try a new, blank disk and use some bootdisk from i.e.
http://www.bootdisk.com
Normally, you can create a Bootdisk under MS-DOS by entering
sys a:
but as most people nowadays don't seem to have DOS installed on their machines any more (I still install it on every machine as an emergency system and for old DOS-games

), they are dependent on bootdisk-images like the ones from
www.bootdisk.com (for german bootdisks, you can visit my site
http://bootdisk.ipax.tk)