I want to sell my old laptop and I want to be 100% sure that no data can be recovered on it. The safest idea seems to me to simply replace the hard drives. However, I'm not a blatant computer expert and do not know if you will not leave any data after all.
Can someone tell me more?
No. When the hard drive is gone, everything is gone.
Data is only saved on the disk or SSD. If they have been removed, your data will also be removed.
Format hard drive -> everything gone
Still recoverable
To erase the hard drive, you should overwrite it with zeros. There's the tool Darik's Boot and Nuke https://dban.org/ Click on Download DBAN. This version is free for private use. After the download you will receive an ISO file. Then write this with Rufus https://rufus.ie/ on an empty formatted USB stick. Then you have a bootable stick.
Simply boot this stick and follow the instructions of the assistant. Then the hard disk is overwritten with zeros.
That's right, so you have to use a program to "safely delete data"
No. After that, only the table of contents is gone. The book is still there. (So as an analogy)
With quick formatting yes. With normal formatting, everything is overwritten with zeros.
Overwriting couple times with / dev / random is still better.
Anyway.
