Hi Dolores! Despite the warning you're seeing on-screen, go ahead and power the computer off (you may need to hold the power button in for up to 20 seconds to get the computer to turn completely off). Afterward, please leave the computer powered down for about 30 seconds, and then go ahead and turn it back on. This should bring your computer "back to life!"
This problem doesn't occur often when installing updates...but, that said, it's not exactly rare, either. Generally you would want to heed the advice given on-screen and not shut the computer down in the middle, but when it freezes up on you like this there's really not anything else to do!
Please reconnect to us here at my.justanswer.com once you've tried out the above just so we know your problem has been resolved. Many thanks!
Hi Dolores! It's been awhile since we chatted, so I wanted to touch base and make sure that you were able to regain access to your computer?
Would you please let me know? Thanks...I look forward to hearing from you!