For syslinux to be installed there MUST be a file named ldlinux.sys on the root of the usb
it may be a hidden file...?
I suggest you re-install a new version of syslinux
here is 3.83 version new
LINK>
syslinux
put that in the syslinux folder or anywhere
cd to where you put the syslinux
Code:
cd /path/to/syslinux
so, if you put it on usb, in syslinux folder, mounted on /media/disk
it would be
Code:
cd /media/disk/syslinux
Now, install syslinux to usb
Code:
./syslinux -sf /dev/sdxx
where sdxx is your usb; sdb1, etc
you gotta use the ./ or it will just install your OS's syslinux