How Do I Properly Wipe My Laptop HDD After Backing Up My Data?

For a complete wipe of your HDD, especially if it's a traditional hard disk drive, you can use a tool called DBAN. You'll need to create a bootable USB with it using Rufus. Remember to disconnect any drives you want to keep safe before wiping! Here’s a decent guide on how to do that: Creating a Bootable USB for DBAN. Just be cautious!

If you just want to back up your files, you can simply drag and drop them to your external drive. If you're switching to a new operating system, the wiping can usually be done during the OS setup itself—just make sure to delete all partitions then. But do check that all your important files are transferred before wiping, since recovering forgotten files can be expensive and tricky.

Don’t forget to back up your bookmarks and any data from installed applications, as those can sometimes be hidden in unusual places. Just make sure you know why you're wiping the laptop—are you reinstalling the OS or getting rid of the machine? If it’s the latter, it's good to keep the laptop around for a bit after setting up the new one just in case you need to grab files you forgot.