Computers do go down during Christmas so test all your computers for the coming holidays. It is much easier to get your computers fixed now than over Christmas. Every computer will fail. It is a matter of time, and the time they like by Murphy's law is the worst possible time: Christmas!
Give all your computers a test run now.
Also, make sure your backups are working. Worst case, your computer is replaceable, but your information is not without a backup. With a good backup, we often need to replace the computer, and you can be back up and running in a day.