Hi Elaine,
I get the impression that things were ok,
until you did something on your PC which resulted
in this condition.
I assume your monitor is ok,
and that you are sure it is ok,
and plugged into to your PC and switched on.
You say:
I can't even get a screen up so that I can get into the Device Manager.
That would be Windows, to get to device manager.
But does anything else show on your monitor?
Is it black screen with white writing on it?
If not,
What noises does your PC make during start up?
Any beeps? describe carefully ... "2 long, 3 short"
Does the floppy unit try to run?
Is your monitor supply fed from the PC,
can you start the monitor before the PC
so as you dont miss anything?
Are there any messages at all on the monitor?
You mention 'lock' and 'lock opener' is there an
icon of a key?
Or does it say locked?
Maybe you or someone put a BIOS password into it?
Please give as much info as you can,
And come back soon!,
John