I installed a board in my XPS Special Edition Tower; it emulates a SCSI drive and will allow me to move files off an old audio recording system and onto my PC for editing.  I keep getting a driver error despite the driver having a legitimate signature.  The guy who owns the company, Bill, that makes the board & software has been trying to help me disable the feature that checks for valid signatures on drivers but we get an error when attempting (spelling might not be quite right as he was trying it remotely and I was just watching the screen) to run "BDSedit /set testsigning on" from the command prompt.  The error is something to the effect that changing this parameter is not allowed.  Bill told me that we need to get into the BIOS to toggle that feature.  However, when I reboot and attempt to enter the mode, that in the old days would allow you access to the BIOS (via repeatedly tapping F2 or F10 or F12 or ESC; we tried them all), I just get the windows sign in screen after a very long boot process.  Bill thinks it's because I am using the HDMI port to connect to a flat screen TV that I use as a monitor.  He thinks that I'm not seeing the screens that would otherwise be seen because the driver for the HDMI isn't loading in time for me to see that screen and that the long boot is due to the timing out of the window where you'd have that option (if you could see it).  Kind of hard to articulate this clearly but, anyone have any ideas how to fix my problem?