I Cannot Leave SA

I have been trying to figure out how to fix my computer for about 2-3 years now. Every time, I just give up. I cannot leave SupportAssist and it is driving my crazy. I got to Continue, and it gives me a black screen, then goes back to saying the AC power adapter wattage and type cannot be determined. I then go tho BIOS setup/Diagnostics, and it does the same thing, except the intended screen will often come up. I've tried pressing all the F buttons and all the regular keys, but nothing works. I've played around with it time after time after time and just cant leave SA.

Please please please! Help me fix this! I wish to get back to being able to use my computer