Something that works on any hard drive, and allows you to set up a hash to completely overwrite the hard drive where you will have to install a new OS is Acronis. It is a backup software that also allows you to fully scrub a hard drive!! It is almost impossible to recover every bit of data. If a person did run recovery, they would get gobbledygook.
As a reference: I am a retired IT. I have used this extensively.
Something that works on any hard drive, and allows you to set up a hash to completely overwrite the hard drive where you will have to install a new OS is Acronis. It is a backup software that also allows you to fully scrub a hard drive!! It is almost impossible to recover every bit of data. If a person did run recovery, they would get gobbledygook.
As a reference: I am a retired IT. I have used this extensively.