how do you disable the Dell 'billboard'
In the bios, there should be a setting to disable Splash Screen. Being proprietary, it might not be there. Never owned one, so I don't know.
for what purpose?
If you're asking why it's there...it's nothing more than advertisement. If you're asking why disable it.....that's where your post is showing (underneath it) on the screen at boot. That's also where it tells you
why it stopped.
I've been running this backup app on this setup for nearly a year without any hiccups. However, I have it running multiple backup profiles in parallel, also running backups from both the 'server' itself and a notebook to the same USB drive at roughly the same time - you think that volume of data could overwhelm USB2?
Absolutely. The speed of USB 1.0 or 2.0 is inherently slow. There was a time that it could run in a 'normal' system without being demonstratively evident of its shortcomings. Those days are long gone. My recommendation (if you want one) is to get an external eSata drive. Even with that, I would still monitor as to how much data from different sources I was attempting to write at the same time....there's only one arm dancing on that platter.
However, the MB apparently gave an error code during the initial troubleshoot. And it wouldn't boot after powering off the USB drives (I have two, one former boot drive that is a data source and the Seagate for daily backups).
When your USB went off line (errored out), it borked the bios boot sequence. My guess is you also have a wireless keyboard/mouse. Thus the beeps. Proprietary boards have no means by which to initialize USB devices, so it just stalled before it could get to the Windows drivers load (that's why active drive image restores via a USB drive are problematic). When he/you reset the bios defaults, the active drive (C:) was restored. If this happens again, plug in a PSU keyboard and access the bios to reset defaults. Failing that, short the JBAT jumper or pull the battery for thirty seconds.