Keyboard is frozen after login. Pointer locked in upper left corner

Hi - My keyboard works fine, at the login stage. After the successful login, the keyboard does not work and the pointer is locked in the upper left corner of the screen. I tried starting in safe mode, but the keyboard does not work in safe mode. Verbose mode simply runs and lands on a screen that rotates between two pictures/images/icons; the first appears to be a picture of a power button and the second appears to be an image of a flash drive with an arrow pointing at what appear to be an unlock command. Confused. Ran a hardware check and everything passed. Tried to reboot via the internet, and that also landed me at the same alternating two pictures/images/icons.

Thanks for any help.