I have had this happen after an update on a client ACER laptop. When you see the acer logo you should see in the bottom right corner a icon button circle with a vertical line ( power shut down icon) press the shift key as you press this icon button and reboot the laptop. It will boot into the repair console where you can choose topics, browse the options to find the start up repair option and choose this, usually it will come back to welcome screen and be fine, some times you have to go thru this again and choose another repair option and in the last case rebuild back to factory as a last resort you will loose your data. If none of the repair tools work it is essential to hook the hard drive to another computer and retrieve your data (pictures, documents, etc) as the hard drive is essentially the same as the larger SATA drives it can be attached to a desktop computer power and serial plug then let it hang not touching anything to short out, even put in a zip lock bag for this purpose. Access the drive and find your account and drill down to your picture folder and document, video folders to get your data, if you are resourceful you can also get your email folder and bring back your email if you look carefully. A repair shop would have a external device to access your drive and do this for you if you want to spend the money, then rebuild to factory. Windows 10 seems to get lost in finishing a upgrade and I have 99% had the start up repair choice work. Some times the hard drive has a fault and some new files do not get installed so gathering your data and rebuild works with some having to replace the drive.
Long text here but me doing it and explaining is a whole different chore, I run thru things as I work and do not see all the choices or screens I go to, it is tough to remember each screen so excuse the actual real steps. I give you a exercise to try and help, you have to have the brains to try it.