|Often when registry entry errors are reported it is due to RAM problems. Try removing the RAM and cleaning the edge connectors with a pencil eraser, then pop the RAM sticks in and out a few times to clear any oxide off the sockets themselves.|
If necessary you can download a free RAM checker to run on either floppy or CD.
The above are for the original fault. I can't comment on the password issue that arrived after your further intervention.
Always pop back and let us know the outcome - thanks