Stuck on Boot and App menu and Norton Bootable Recovery Tool keeps failing?

Hi, I have major computer problems going on and would appreciate any help.

The problem is my Lenovo Windows 8 is stuck on the Boot and App Menu after being slow and quiting, I'm guessing a virus attack. I tried suggestions like changing some settings, killing the power but it doesn't work, the power button still leads me to the same screen.
Any other way out of it?

I have also tried the Norton Bootable Recovery Tool. I did the USB thing from a good computer and used it on mine and seems to work until I click the "Agree" button for Terms and Agreement and says an unknown error has ocurred and then restarts itself. I put on Wi-Fi but it doesn't help.
Why isn't it working?

Hold the power button down for more than 5 seconds to switch off then restart in safe mode and run the malware and antivirus programs then