The most common preventable loss is not the hardware failure itself, but someone reinstalling or reformatting in a hurry before anyone looked at the disk. If the machine is dead, stop and ask first.
Two habits worth having before you need them: know where your backup goes and confirm you can actually open one. A backup nobody has ever restored is a hope, not a backup. Check this on a quiet day, not on the day the machine dies.
Since you will likely buy a replacement computer locally, this is also the moment the earlier advice pays off — separate components rather than an all-in-one, because you only have to replace the part that failed.