So you have finally decided to trade in your old desktop or notebook PC for a new model. But before you resell or recycle it, you need to ensure that none of the personal data stored on your PC gets into the hands of whoever uses it next.
The quick way, of course, is to just format your hard drive. But if you are reselling the device, deleting Windows 7 or any older version of the OS will diminish its value; after all, your buyer wants a fully functional PC too.
Don’t worry, you can get rid of all your data with the help of a few apps. And don’t forget to back up your data first. Use an external drive, or better still a cloud storage application, to store your important files and documents. Google Drive and Dropbox are great for general storage, while professional solutions like Hightail or Zoho Docs are perfect for secure document storage and management.
Step 1: Backup [Nothing Deleted: Proceed Quickly]
On a portable hard drive or pen drive, backup all the data you want to transfer to your new PC. This is very, very important. All the personal data you have on your disk right now – files, photos, music, etc. – is all going to get wiped out by the end of this guide. So whatever you need or think you might need in the future, back it up.
Step 2: Download The Apps [Nothing Deleted: Proceed Quickly]
Before we get into the guide, I’m going to insist that your first task be to download the following apps:
Step 3: Disconnect [Nothing Deleted: Proceed Quickly]
The reason I asked you to download those apps in the first step is because you are now going to disconnect from the internet, never to connect to this PC again. This is an important step because you don’t want some minor change you make to affect any cloud-connected data, like mistakenly deleting a file from Dropbox.
So go ahead, disconnect your Wi-Fi or unplug your Ethernet cable or USB dongle. That’s the last time you’ll access internet on this PC.
Step 4: End tasks [Nothing Deleted: Proceed Quickly]
Next, we are going to kill all the tasks that are currently running so that, again, there isn’t any problem when uninstalling or deleting data.
Close all the open windows; right-click and exit every icon in your system tray; and finally, run the task manager (Ctrl+Shift+Esc) and stop all the program processes you recognise. Warning: Be careful when stopping processes; if you don’t know what it does, keep it running. For example, ‘Explorer’ means Windows Explorer and not Internet Explorer, so don’t close that.
Just in case you stop an important process in this step, don’t worry. Just reboot and complete Step 3 and Step 4 once again.
Step 5: Uninstalling Programs [Caution: Some data deleted]
This is the first major step in cleaning up data on your hard drive. The programs you have installed need to go first, since they can contain sensitive information. Plus, your buyer wants a clean PC to make his own, not something with a bunch of stuff already on it.
Revo Uninstaller is a fantastic software uninstaller and its free version does the job well enough that you don’t need to spring for the paid variant. Install and run it.
In the main Uninstaller tab, you will see a list of all the programs that have currently been installed on your system. Choose one and click ‘Uninstall’, and say ‘Yes’ when Revo asks if you’re sure you want to uninstall the program.
Select ‘Advanced’ mode and let Revo get to work uninstalling the program. Follow the instructions in the application’s uninstaller, and once that’s done, click ‘Next’ in Revo. It will scan for leftover information in files, folders and registry items related to the program. This can take a while, but be patient.
Revo will then show you a tree of all the registry items made in connection with the program. Select all and hit Delete. In the next window, with a list of all the leftover files and folders, do the same: Select all and Delete.
Hit Finish and move on to the next app installed on your computer, as shown by Revo. Don’t stop till you are done deleting the whole list of programs.
TIP: Some programs prompt to reboot the system for a more thorough uninstallation. Say no. Finish running the Revo Uninstaller for all the programs, and once you’re done, reboot once. After you reboot, make sure you redo Step 3 and Step 4.
Step 6: Wiping Cache And Data [Caution: Substantial data deleted]
Again, the free version of CCleaner is good enough to get the job done. Install and run it, choose the ‘Cleaner’ tab, and check all the boxes in ‘Windows’ and ‘Applications’. Hit the ‘Analyze’ button, which should take a few minutes. Once the analysis is complete, click ‘Run Cleaner’. This wipes out a lot of important data, including temporary files, browser cookies and information, etc.
Then go to the ‘Registry’ tab, make sure all the boxes are checked and hit ‘Scan for Issues’. Once the scan is done, select all the items and click ‘Fix Selected Issues’.
Next, go to the ‘Tools’ tab. The ‘Uninstall’ sub-tab should be empty, except for Ccleaner itself and Revo Uninstaller, since you removed all the other software through Revo. The ‘Startup’ tab might still have some entries, so select and delete each of these. Do the same for System Restore to remove all the restore points you have saved.
Drive Wiper is a good option, but we have something better in the form of Complete Data Wipe.
Step 7: Deleting Personal Data [Extreme Caution: Major Data Delete]
Once again, I hope you have backed up all your important data because this step is going to get rid of everything you have stored on your hard drive.
Install and run Complete Data Wipe, and go to File -> New Task [Ctrl+N]. The ‘Files In Folder’ option is all we will deal with here. If you have multiple partitions, then choose every partition apart from C Drive. Then open C Drive and choose every folder apart from ‘Windows’. Once all of these appear in the Complete Data Wipe list, go to Task -> Run All [Ctrl+Alt+R]. It takes a fair bit of time, but Complete Wipe Data will shred and delete all your files in a way that even recovery programs like Recuva can’t put the files back together again.
Step 8: Deleting Windows Settings [Caution: Settings Delete]
Finally, it’s time to take out a few items deeply rooted into Windows.
First, the network connections. Windows stores WiFi passwords so you don’t have to type them each time. Go to the ‘Network and Sharing Center’ in Control Panel, and click ‘Manage Network Connections’ in the left panel. Right-click every network listed there, and choose ‘Remove Network’.
Second, it’s time to delete all the user accounts. Before you start, make sure you log off and log back in as the default Administrator. Next, hit the Start button, type ‘User Accounts’ and hit Enter. Click ‘Manage another account’ in the options. Choose any account apart the Administrator you are currently operating and delete the account. When it asks where to keep or delete files, choose Delete Files.
This is a bit paranoid, but just in case you want to be really, really, really sure all your data is wiped clean, I’d recommend you run Step 7 one more time at this point.
And just like that, you’re done! Reboot once and make sure all the data is gone. Time to resell/recycle that PC!
Update: This post was originally published on December 12 2012. It was updated on 15 June 2015.