My computer will not start after the toshiba screen comes up. The screen is black with a blinking cursor

Can u get into bios check boot order or see if hdd is readin or 1st 2 boot

That might be caused with a lot things maybe RAM, maybe a corrupted OS, or might be a loose connection of the hard drive, maybe a virus or a malware. If you can go safe mode( by pressing f8 during boot up)run your anti virus from there if that didn't work try your system restore. If that didn't work try removing your RAM and replace it (you must have a back up RAM at least for testing purposes). If that didn't work also try removing your Hard Drive. Remove it carefully then carefully re install it.(Remember to pull out the battery and the charger before removing your Hard Drive and RAM for safety precautions) If neither of the above worked, then clean installing your OS is your last option.
Good Day.