The R210II has a slightly different bios from other 11g systems, here are the steps to boot to usb. 1. during bootup, press F11 when prompted in the upper right corner 2. Select Boot Settings then press key.  3. Select Set Legacy HardDisk Drive Order then press key.  4. Select HardDisk Drive #00 then press key.  5. Select USB device what you want to boot then press key.  6. You will see the HDD boot order has been changed. 7. Press key and press key to save the HDD boot order.  8. Select HardDisk group then press key to boot to the USB drive. 
I want to do an install of Windows 7 Pro, but I can't figure out how to get the machine to boot off a USB stick. No BIOS option that I see. My next option is to disassemble and add a drive to get the OS installed, but I'd rather not do that if possible. Any suggestions?
Can't figure out how to boot R210 II from USB