WEE, is a bootloader based on grub4dos. It fits in the first 63 sectors of the drive. The first 4 bytes are: $ hexdump -n 4 /media/Data/ubcd-new/wee-2010-06-20/wee63.mbr 0000000 5eeb 0090 0000004 Or in the format get_mbr_string wants it: $ hexdump -C -n 4 wee63.mbr 00000000 eb 5e 90 00 |.^..| 00000004 Patch tested in qemu: qemu -boot d -cdrom hdt.iso -hda wee-2010-06-20/wee63.mbr - Gert Hulselmans diff -up -r syslinux-4.00-pre58/com32/gpllib/disk/mbrs.c syslinux-wee/com32/gpllib/disk/mbrs.c --- syslinux-4.00-pre58/com32/gpllib/disk/mbrs.c 2010-06-23 02:09:52.000000000 +0200 +++ syslinux-wee/com32/gpllib/disk/mbrs.c 2010-06-23 21:28:05.035597445 +0200 @@ -71,6 +71,8 @@ void get_mbr_string(const uint32_t label strlcpy(buffer, "fbinst", buffer_size - 1); else if (((label >> 8) & 0xff) == 0x80) strlcpy(buffer, "Grub4Dos", buffer_size - 1); + else if (((label >> 8) & 0xff) == 0x90) + strlcpy(buffer, "WEE", buffer_size - 1); else strlcpy(buffer, "Unknown mbr", buffer_size - 1); break;