Sell a laptop - delete data?

If I want to sell my laptop, what do I have to do, that all the data is erased and can't be made anymore…

There was a technician uni who bought several pcs, laptops, hard disks, etc. And tried to restore the data and it has always worked out the only way to erase the data to 100% is either the microwave (n bit sparks jump) or the Hammer.

HDD: All you need is a low-level format
SSD: If the SecureErase masters => Run. Otherwise keep SSD.

For both actions, remove the disks and delete them on another computer.

You could format the hard drive, reinstall Windows and then clean up the free memory with SDelete.

https://docs.microsoft.com/...ds/sdelete