My mother's new computer is acting up. It was fine for most of the day, but now nothing is working. All the apps on the start screen have X's in the corners, and will not launch. Firefox opens, but will not load a page. I tried everything I thought might work, but nothing does. I would be very appreciative if someone could help us.

Try out the "Refresh" option. Settings > General > Refresh My PC. It should remove all programs and restore Windows to its original state. You will need to reinstall your programs, but it won't affect other files.