i tested one time the magic usb boot, with some codes, from one sector to 64k bytes.

above 2k (4 sectors) the geometry isn't the same between bios INT13h and win98 INT13h.

i use 98 to write with int13h on usb pen, and apparentlly, there is a big problem of compatibility, and that's why i gave up one year ago.

then, if someone have a solution (or explication) to fix this f***ing bug, i am open. thanks.

edfed,

There is no standard for CHS translation, hence we have ECHS/Large, revised ECHS, LBA-assisted CHS (and some bugged implementations of those as well ). Try to fdisk / format your UFD from plain DOS, this method saved me once (Windows seems to use partition table contents as a hint to calculate drive logical geometry).