How to Leave No Trace on a Borrowed Computer

By David Nield on at

Say you need to borrow someone else’s laptop or desktop, but you don’t want to leave a digital trail of breadcrumbs behind you when you’ve gone. Maybe you’re using a public computer, or maybe you’re just borrowing a friend’s and don’t want to mess up all their own settings and preferences too much — how do you make sure you don’t leave any tracks? Commit these tips to memory and use them whenever the situation arises.

Browse privately

If you’re doing something on the web, the private mode in whatever browser is installed is a quick and effective way of covering your tracks. It’s also the easiest way to log into your own online accounts without interfering with the accounts and logins of your partner, uncle, cousin, colleague, or whoever it is you’re borrowing the computer from.

For the uninitiated, private or incognito mode keeps no record of your browsing: When you close the browser tab, as far as the browser is concerned, it’s like your online activities never took place. Launch it via New Incognito Window from the Chrome menu, New Private Window from the Firefox menu, New InPrivate window from the Edge menu, and New Private Window from the File menu in Safari on a Mac.


Screenshot: Gizmodo

When you’re done, close the window and walk away. Note, however, that private windows don’t delete files you’ve downloaded or bookmarks you’ve created — as long as you don’t do any bookmarking or downloading, you should be fine.

We should mention a caveat, which is that the sites you log into will know that you’ve logged in... it might sound obvious, but if you’re shopping for a gift for a special someone, and you’re logged into a joint Amazon account you share with them, the search history will still be accessible through Amazon (whether or not you use private mode).


Screenshot: Gizmodo

Should you realise too late that you’re not in private or incognito mode, you can erase all records of online activity (cookies, browsing history) over the last few hours. In Chrome, pick Settings from the menu, then Advanced and Clear browsing data. In Firefox, choose Options from the menu, then Privacy & Security and Clear History.

On Microsoft Edge, you need to open the app menu then pick Settings, Privacy & Security, and Choose what to clear.

Safari’s controls aren’t as granular, but you can blitz everything by choosing History and Clear History, as well as Safari, Preferences, Privacy, and Manage Website Data.

Clear histories

Most apps you use will have some kind of history feature, and so do Windows and macOS. If you’ve been hunting around for and opening stuff, make sure you clear whatever app and OS records need to be cleared before heading on your way.

In File Explorer in Windows, for example, click inside the search box (top right) to bring up the Search tab at the top. Choose Recent searches to see recent searches, and Clear search history to wipe them. To clear searches made from the taskbar, click inside the taskbar search box, then open the menu (three dots, top right) and choose Search settings. Select Permissions & History to see your options.


Screenshot: Gizmodo

Assuming the computer owner hasn’t signed in with a Microsoft account (if they have, you’ll have to leave these particular records in place unless you know their password), you can toggle the View activity history switch to Off and click Clear my device history to cover up your tracks.

If you’ve been opening up files, this’ll show in the Quick access section of File Explorer on Windows by default. If you’d rather that wasn’t the case, right-click on the Quick access heading in the navigation pane on the left, then choose Options: Under General click Clear next to Clear File Explorer history.


Screenshot: Gizmodo

It’s harder to completely erase your activities on macOS, but there are a couple of places worth checking. Click the Apple menu then Recent Items and Clear Menu to clear that particular list, then open up Finder, click Go, and choose Recent Folders then Clear Menu.

Saving files to disk is best avoided if you’re trying to be untraceable, but if you have saved any files, you need to delete them and bypass the Recycle Bin or Trash. On Windows, hold down Shift and hit Delete to permanently delete a file; on macOS, Option+Cmd+Backspace is the shortcut you want.

Individual programs

We can’t walk you through every single application you might use on Windows or macOS, so you might have to do some detective work of your own and look for ways of tidying up after yourself. In any Office desktop program, for instance, you can right-click on a file in the Recent list and choose Remove from list to do just that.

If you’ve been using Photoshop, meanwhile, you need to click File then Open Recent then Clear Recent File List to cover your tracks (as well as deleting the files you were working on). Most apps come with some kind of history cleaner like this, so have a hunt around (preferably before you get started, if you want to stay incognito).


Screenshot: Gizmodo

Sometimes you won’t be able to clear traces of your activity, but it helps to be aware of when this is the case. If you borrow someone’s Spotify account, you can’t hide the listening history from the account owner, so bear that in mind (though you can sign in and then out of your own account if you’ve got one).

Even if you don’t mind the owner of the computer you’ve borrowed knowing you’ve been on Gmail, Twitter, or whatever site you’ve been using, make sure you don’t let the browser log your username and password, and make sure you sign out when you’ve finished.


Screenshot: Gizmodo

If you find yourself jumping between a lot of computers and want to minimise what you leave behind, consider sticking some portable apps on a USB stick. Getting one set up is a whole separate guide itself, but it’s not difficult to do — we’ve written up the process here and you can get started in minutes.

All your apps and files and settings are stored on the USB drive, so as soon as you yank it out of the other computer, it’s like you were never there. Check out the Portable Freeware Collection and PortableApps.com for some of the apps you can use — they include web browsers, email clients, office suites, media players, and more.

Featured image: Ales Nesetril (Unsplash)