I shutdown my laptop a few days ago. I returned to it last night, turned it on and it was on the logging off screen. I waited and waited. I turned it off and turned it back on. Still on the logging off screen. I let it sit overnight with no success.

Was it turned off, or was it going into Sleep or Hibernate?

Try holding down the power button until the light in it goes out (a minute or two is usually required).
Just to be sure, remove the battery and the power cord and let it sit for a while.
Then hold the power button down for about 30 seconds (everything unplugged and out)
Then put the battery back in, plug in the power cord and try to start up.

If it asks about restoration data - tell it to delete it and restart.

I suspect that the Sleep/Hibernate file on the hard drive is corrupted and is causing these issues. Once in Windows, I'd recommend updating your video drivers to the latest WHQL certified version available from the manufacturer of your video chipset (not the PC manufacturer)

If you need more info on this, please post back with the exact make and model of your laptop.

I had turned it off, I belive, and has been off for several days.

I will try your suggestions and let you know how it goes.

I just purchased this laptop last month. It is an HP dv97..., can't remember the exact model number.

Thank you for your help!