As an IT consultant, I can tell you that there could be several causes for that condition, most of which are pretty simple. You should be given the option to go back to the last saved state that worked too. Hopefully, your friend will have a bootable tech thumb-drive that will allow him to confirm whether it's SSD-related or just a Windows Update issue (something I see a lot - I've got an entire folder dedicated to a few dozen update errors and what to do to fix them).
That said, if it DOES require going into the laptop, having someone who's done it before can help (there are also videos on YouTube that show exactly how to get in). Laptops can be very annoying in that manufacturers tend to hide some of the access screws under labels and rubber feet (again, check YouTube for your exact model!). Be very careful to know where the screws go back to as well! Some laptops have different sized screws for different locations - make sure you note this on paper so you can reassemble things correctly if you do it yourself.