I booted the above mentioned laptop from the hard drive into Windows with no problem. There were no passwords involved.
I then tried to boot the laptop with a usb stick. In order to do that i went into the (Phoenix) BIOS. There was no separate entry for the stick but it appeared as a subnode of HDD at the same depth as, but below, its sibling node - the 'real' hdd. OK, so i did the obvious thing and raised the stick in the order so it appeared above its sibling, saved the settings and rebooted.
This is where the problem started: the system then came up with an HDD password prompt.
This is not my machine and neither i nor anyone else connected with it knows anything about a password. I'm now locked out of the machine.
With any luck, this is a security 'feature' (thanks Phoenix/Acer) and someone will know how to get out of this mess. Do YOU?