Ask LH: What Should I Do To My Computer Before I Sell It?

Dear Lifehacker, I know I should securely wipe my hard drive before I sell it, but is there anything else I should do before I put it up on eBay? I want to make the transition as smooth as possible. Sincerely, Selling it All

Dear SA,

Selling (or giving away) an old computer is often a little scary. You likely invested a lot of hours into using your computer, and it’s packed full of all your personal stuff. You also want to make sure it’s in tip-top running condition before you sell it off so you can get the most money. Here’s what you need to do.

Step 1: Back Up All Your Files

The first thing you want to do is make sure you back up everything you need. How you do this really depends on what you have on your computer. If you just need to hold onto a few files, Dropbox (or any cloud storage service) will do the trick. Alternately, you can easily back up your data to an external hard drive.

If you’re going to go a little while between computers, a cloud backup solution like Crashplan might be a good bet, and it’s very easy to back up and restore your data. Regardless of what method you choose, make sure you run the backup before you do anything else so all your files are up to date.

Step 2: Deauthorise Any Software

Next, deauthorise any digital software or files you have. This includes programs like the Adobe Creative Suite, Amazon’s Kindle Apps, and files you download from online stores like iTunes.

Likewise, it might be a good time to clean up the services you enabled two-factor authentication on. While the chances of someone having your password after you securely delete your hard drive in the next step is slim, it’s a good idea to make the process of someone logging into your accounts impossible from the start.

One last thing to note before we delete everything: if you’re a Mac user running OS X Mountain Lion or OS X Lion, you might need to make your own USB or DVD boot disc so you can easily reinstall the OS in step 4. You can also download and install the OS during the re-installation process, but a physical copy of the OS will put your mind at ease just in case things don’t go as planned.

Step 3: Securely Format Your Hard Drive

The only secure way to clean out your computer’s hard drive is to format it so you start from scratch. This process is time-consuming, but it’s necessary before you sell your computer to stranger. You don’t want any personal information remaining on the hard drive.

We’ve walked you through this process before, and it’s very simple. On Windows, we like the program Darik’s Boot and Nuke to format the hard drive, and on Mac the built-in Disk Utility works great. Photo by Kevin Walter.

Step 4: Reinstall the Operating System

Once your hard drive is formatted, you won’t have anything on it. This means you need to reinstall an operating system before you sell it. The process is easy provided you still have your operating system discs. Reboot the system, and boot from the OS disc itself. Windows should automatically boot from the disc, but if not you can change the settings in your BIOS to make it work. For Mac, hold down the Option key after you hear the startup chime and select your boot disc (the USB or DVD you made yourself in step two).

Once you’re done reinstalling the operating system, it’s up to you how far into the setup process you want to go. If you’re selling a computer online at a site like eBay, you can stop at the new user creation screen. Just power off your computer when it asks you to create a user account and you’re good to go.

Step 5: Clean it Up

Finally, clean up the computer and make it as nice as possible before you sell it. Not only will it likely sell for more if it looks good, it might also run a little smoother. As we’ve talked about before, you should do a few simple things: wipe down the computer, clean out the keyboard, clean the screen, and pop it open to clean out dust from the inside. This makes the computer a lot more aesthetically appealing, and that makes it easier to sell.

Once your computer is cleaned up and it’s looking as good as new, take some great pictures of your computer, and then you’re good to post it online.


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