Black screen on boot up

I've been suffering with the black screen on boot up problem - it just

appeared overnight on a previously working install.

I've managed to (temporarily more than likely) solve the problem by

unplugging a number of USB devices which were, prior to physically moving

the PC, plugged in to different USB ports on the mobo. I had these USB

devices plugged in to these original ports when I installed Vista - the

problem started after moving the PC and plugging the devices in to different

ports. If I plug the USB devices in to the mobo and boot the PC Vista will

oftenboot to the black unresponsive desktop (just the mouse pointer on the

screen and nothing else). It seems possible that, for some reason, the black

screen is being caused on boot up by certain USB devices being connected to

ports different from the ones they were connected to when Vista was

installed.

Has MS given any indication that it is taking the black screen of death on

boot up seriously? I can find no solution or mention on the MS website

despite many posts to many forums describing the problem.

Gareth.