Tech security tip: How to delete private data for good

Male hand holding smartphone. Businessman using laptop computer and digital tablet while working in the cafe. Mobile app or internet of things concepts. Modern lifestyle in digital age.

Here's how to delete your private data -- for good. (iStock)

Moving a file to the trash on your PC or Mac gets rid of it for good, right? Not so fast.

These files can be seen by others later, and they could be slowing down your machine. Tap or click for my favorite tricks to speed up an older computer.

The contents of your PC’s Recycle Bin or Mac’s Trash Can are only cleared out when you empty them. Until then, there’s a treasure trove of files for someone to snoop through. Worried someone is keeping track of what you do on your computer? Tap or click here for ways to do your own digital sleuthing.

If you haven’t correctly shredded private documents, they can still be found later on down the road — even if you clear your trash can. All it takes is a little know-how to recover them.

I thought that file was deleted. What’s going on?

When a file is deleted, your operating system removes the link to the file and marks the space free. Until it’s overwritten by new information, that file still exists on your hard drive.

Most hard drives are pretty big, so it could be some time until the file is really gone for good. That gives a hacker or a snoop ample opportunity to get his or her hands on your data.

And just think about that old computer you’re going to sell on eBay or take to Goodwill. You could be turning over your entire digital life to a stranger. That’s a huge mistake, but I’ve got the steps to help you.

Steps to delete data forever

If you’re serious about your personal security, you need to erase sensitive data for good.

To do it, you need software like Eraser or Blank and Secure for Windows.

Eraser, in particular, has a lot of options for deleting data. It has a simple, clean interface, and can permanently erase data from any drive that works with Windows. You can even schedule deletions to happen automatically.

Blank and Secure is a portable deletion tool you can store on a USB stick. It “shreds” files by overwriting the data with zeros before deleting, making recovery impossible.

When macOS Sierra was released, Apple removed the secure delete option for both the Trash Can and the Terminal. To shred files you’d like to remove from Macs, use a shredding app like Secure File Deletion – Digital File Shredder. It costs $4.99 to download.

For a good free option, try CCleaner. It works with PCs and Macs to automatically clean up your browser cookies, trackers, internet history, download history, cache and even individual session activity. You can also use it to delete files securely.

Go a step further for extra precaution

For an extra layer of security, you can encrypt your hard drive. Your data is converted into an unreadable code that can only be deciphered with a specific key or password with encryption.

PC users can enable Windows’ built-in encryption tool, BitLocker. If you’re looking for another option, VeraCrypt is a free, open-source encryption tool for Windows, Mac and Linux.

Macs have their own built-in disk-encryption tool, too, called FileVault. Similar to BitLocker, it helps prevent unauthorized access to your data and adds an extra layer of security in case your computer is stolen or lost.

FileVault is available for OS X Lion or later. Once it’s turned on, you will always need to login in with your account password.

To set up FileVault, click the Apple menu and select System Preferences. Then click the Security icon and enter your username and password. Open the FileVault tab, then choose Turn on FileVault.

Solid-State Drive manufacturers also include management, encryption and secure deletion tools, so check these available options too.

Need expert tech help you can trust? Post your tech questions and get concrete answers from me, along with other tech pros for 30 days for free. Sign up at GetKim.com, no promo code required.

What digital lifestyle questions do you have? Call Kim’s national radio show and tap or click here to find it on your local radio station. You can listen to or watch The Kim Komando Show on your phone, tablet, television or computer. Or tap or click here for Kim’s free podcasts.

Learn about all the latest technology on The Kim Komando Show, the nation’s largest weekend radio talk show. Kim takes calls and dispenses advice on today’s digital lifestyle, from smartphones and tablets to online privacy and data hacks. For her daily tips, free newsletters and more, visit her website at Komando.com.