-USB HDD in BIOS

[IBMquestion]

I have been having trouble booting to USB on several Lenovo Thinkpad 61's. The USB HDD has a minus sign in front of it. No matter what I do I not able to get USB to show up as an option when I access the boot menu on start up. I can't remove the minus sign. Can someone explain to me what this is? And how to resolve?

[RealBlackStuff]

In BIOS, is the Config/USB/USB-Bios support ENabled?
Always on ENabled?
Have you tried another USB port?
The option Startup/Show F12 boot-options could also be set to disabled in BIOS.