I can not use my computer since the brightness level is on 0%. Last time I used my computer I set the brightness down to zero and in a hurry I closed my laptop like that. Now I turned it back on but the screen continues to be black. Adjustment keys F2and3 on keyboard do not work and yes I have been trying it with fn lock. I can not do a thing since the screen is black. Have been trying to restart it by using onoff button several times, plugged it completely out. Nothing. Screen still black. Help!

THANK you!what about trying to get into the BIOS via Esc, F10 or Del (or whatever it is for your laptop)?
the hope is the laptop won't honour your brightness level when entering BIOS and I've seen some BIOS versions where you can change screen brightness from there.

and just to clarify, you have tried F2 or F3 with the Fn key, what about without it?
as some LAPTOPS have the Fn key preset to ACTIVE or not, meaning to use the F key special action, you only need to hit that F key without Fn.Id boot to safemode and make the corrections there and re-boot...