Really? The OP might as well just hold it under water a while, put a couple of bullets into it, and burn it at the stake.
I think you may have just explained how I beat a very nasty piece of malware I got. It never would completely go away, so I just gave up and installed Linux, repartitioning the drive to do so. When I later reinstalled Windows for a single game that wouldn’t run in Wine, I had no problems, and eventually migrated back to Windows, all without ever having a problem with that malware again.
So instead, since they know so little, you encourage them to replace the hard drive on a laptop? I could print out and snail mail a step by step pictorial on how to fix the master boot record on any windows machine.
Not quite the same if I want a clueless person to swap and configure a hard drive for one of many gazillion possible configurations. Fix the friggen mbr. It’s cheaper, less invasive, and just as effective.
I would trust a clueless person to swap a drive correctly more than I would trust a clueless person to clear the MBR. I’ve easily talked my father-in-laws through swapping cards and even replacing the power supply. But when I try to talk him through software fixes, it’s like he’s never used a computer before.
If you know what you’re doing it’s not hard to clear the MBR, but I don’t get the sense that the OP or the in-laws are tech savvy enough to know they did it correctly. If they don’t clear the MBR, they stand the risk of reinfection the next time they boot. If you were on the phone with them, you could probably talk them through what needed to be done and verify it was done correctly. But if they do it on their own, they may make a mistake. In this particular situation, I don’t think it’s worth trying to save a few bucks on the drive. We have to assume the MBR is infected.
By replacing the drive they still have all their original files on the old drive. They don’t have to copy everything to CD before doing a reinstall. This way they can retrieve the files at their leisure and they don’t risk losing anything.
It’s cheaper to clear the MBR, but I don’t think it’s easier in this case. If you clear the MBR and reinstall the old drive, you first need to backup all the files. If you don’t mind spending a few bucks on a new drive, you will save yourself the hassle of having to do a backup first. Plus, you now have an external drive you can use for backups in the future.
If someone came into my shop saying this, I would tell them they got bad advice and my advice is to worst case wipe and reload on same drive, and this is coming from someone who would make more money selling you a hard drive.
I wouldn’t even bother reformatting if the machine is otherwise working, hit them with a cocktail of AV apps and call t good. AVG, SAS, Malwarebytes, combofix. 95% of the time you have a squeaky clean system no matter what they did after that.
Once you do this, the drive is clean, you could have reloaded windows and been fine.
Make sure that the wifi is turned off while as well. If you start the computer you never what it is trying to hook up with.