USB stick has to be fat32 formated. Smaller sticks work better.
Make sure the recovery files are in the root directory,
edit the startup.nsh so that the runs the XXXRec.cap
and last, use the same rec.cap as the BIOS you wiped out.
Unplug any other HDDs or fob drives (the recovery needs to be FS0: to FS3: as i recall.