ISO download from Microsoft directly. Use Rufus to make an installer USB. Click the "I do not have a license key" option. Who cares about the watermark.
I'd start there and see if it can be used for 11 or upgraded through the versions. Then I'd take a "clean" backup and use that to re-install in the future, instead of a new ISO.
If the laptop came preinstalled with Windows you can likely reinstall the same version (Home or Pro) by using the utility from Microsoft to build a bootable USB drive, and it will auto-activate.
No need to pirate anything, you already have a license.
Well, it is technically "piracy" but it's amateur piracy. No need to get fancy with torrents and VPNs or whatnot. Just download the software and... not pay.
Safest image download would be from Microsoft website. You need activation? Look up Microsoft Activation Script (MAS) on Github. Read the readme on how to use it.
Just reinstall it via Microsoft official iso maker. Anything newer than Windows 8 will attach license keys to the hardware (motherboard) and it usually picks the activation right back up.
This is the way. Win is already activated, no need to pirate anything. Just get a >= 8gb flash drive, download the installer creator app from Microsoft, and reinstall Windows. It will activate based on the licensing level the machine came with, minus the crapware, which is from the manufacturer's OS image, not Microsoft's.
This OP, also make sure to choose custom install and delete ALL the partitions. Not only does the manufacturer image reside there with it's crapware, it could have been tampered with to reinstall all that malware lol
Considering it's a laptop with a working Windows, it probably already has a licence for the hardware. Just download from Microsoft, wipe disk and install it and see if it works.
NGL I'm so tired right now I thought you were serious about there being a "Windows Debian Edition"
I even googled it lol
I do agree though that if your mum only uses the PC for like day to day browsing she'll never notice a difference if you put a Windows style skin on your preferred Linux distro. Hell she might notice it being faster all around to be honest.
Except if the malware has already infected the recovery partition or completely removed it. Personally I'd take no chances and just nuke the HDD and perform a fresh install.
Find out what version of windows that laptop ships with, and install that. Windows licenses have been tied to mobos for a while, there's a good chance it'll just activate. If you need an installer, you can download ISOs and tools to make a bootable USB from Microsoft's site.
Like others have said, just use official windows and don't activate, only downside is the watermark afaik.
Alternatively, you can buy licences for like 1-2 $ off eBay and other similar sites. Just make sure the licence and the version you install matches otherwise it won't activate
Use the official Microsoft tool that makes installation media. From there, you can leave it unactivated, purchase a key, or use MAS or whatever it's called to activate for free
Mmmm you're talking about key resellers. A full retail version costs $150. Keys from key resellers are notoriously unreliable. It might work forever, or it might stop working a week after you authenticated. It's more or less a gamble.
Great if it works for you, sucks if someone just wasted money (however little) on something that'll stop working - especially if it's grandma's machine.
Also, hedge your bets a little better, buy the ones that cost $10 or even $15. Historically speaking those are a safer bet.