Updating from Sierra to High Sierra

I have an early 2011 MacBook Pro and have repeatedly tried unsuccessfully to update the software from Sierra to High Sierra. Every time I have done so I receive the message 'MacOS High Sierra could not be installed on your computer. An error occurred while verifying firmware. Quit the install to restart your computer and try again.'

Is there anything I can do? I've read a lot of comments about computers beach balling and being really slow after the upgrade so is it just time for a new computer?

klj59