Ask the friend or family member to go out to their local electronics megastore & purchase an external, portable, USB powered hard drive "of the largest capacity you can comfortably afford".
Use that drive to make a clone image of their machine to, then set up an auto backup schedule to save their files to the drive.
If something goes titsup on the machine then you'll have a System Image you can use to Restore to, plus their data files to recover.
If you also make a directory on the drive with all the drivers the machine needs to apply from a complete clean install, then they'll be available OffLine should the need ever arise.
Teach them what the Emergency Boot Disk is for, show them how to use it, & tell them to call you if they ever feel the need to use it so you can walk them through it & make sure they do it right.
If you give them basic tools to help themselves & the knowledge of how to use them, then they may (*may*) develop the confidence to USE them when it hits the fan.
I used to make a "Nuke & Pave CD/DVD" for just such occasions, updating it to include the appropriate drivers the specific machine required, various tools to use (from either a DOS prompt, Windows in Safe Mode, or as a LiveCD), and then make the clone to a hard drive for my customers. Tape the CD/DVD into the inside panel of the case, wrap the drive with the restore image on it in bubble wrap & an antistatic sleeve, & leave it in the bottom of the case with a note letting them know what it was for. If any other tech opened the case they'd find the CD/DVD with the latest drivers, antivirus, anti malware, tools, et al & a HDD with a restore image + clone of the original drive, ready & waiting to help. If *I* was that tech then I could have the system restored toot sweet & reloading all the security updates from the image's date of creation. Friends, family, & clients loved the fact that I could get them back up & running so quickly, and the fact that I told them how to do it themselves helped give them the confidence to know they COULD do it if needed.
So take a good sized USB FlashDrive, turn it into a LiveBoot device, load it with drivers & tools, and slap a clone image of the HDD on it for restoring. You can tell them to put the USB stick somewhere safe, and use it for the same purpose as my old N&P disks + clone image on HDD. Simply plug it in, reboot, pick the USB stick from the boot menu, & follow the prompts to restore the drive to a useable state. Bonus points if it automaticly backs up their User Space to the 'Stick first & then copies it back afterwards.