you cant modify syslinux.cfg for windows boot, it is setup for linux only, unless theres some kind of change to syslinux i dont know about.
My only question is that did you do a USB w/ persistent changes install to USB/SD or Did you actually install the BT onto your harddrive.
Harddrive:-->edit lilo
USB/SD:--> cant edit syslinux for Windows(srry)



