Webroot is a legit antimalware product, but it probably won't be as good as the included Windows Defender in Windows 10/11.
It was probably preinstalled with the machine, so it's safe to uninstall it. Although, you or your neighbour should probably reinstall Windows to remove all the OEM crap (make sure to download it from Microsoft though)
Anything important will need to be backed up before reinstalling, as data will be wiped. 90% of the time, any drivers that need to be installed will be automatically be installed when the machine is connected to the internet.