2.5" HDD and SSDwhat drive do you have? 3.5"/2.5" hdd or 2.5" ssd or m.2 ssd or m.2 nvme?
do you have another desktop pc in which you can plug the drives into?2.5" HDD and SSD
This is the quickest option. Windows media creation tool would be best. As long as you have a spare 8gb usb stick it can be used to install a windows boot to install windows from. The delete partitionsIt sounds as though you just want to quickly wipe the drives so you can reinstall Windows and pass the machine on so the family member can use the machine. In which case, just run Windows installer from a USB stick, erase all partitions from all drives when asked for the installation location, then install Windows.
Are they going to use both a hard drive and SSD? I'd be half tempted to take the hard drive out if the SSD on it's own has enough storage for their needs.
And best way to wipe it in case someone tried to snoop around by recovering files?