Using Shared Computers Safely

Students use shared computers every day: library terminals, department labs, internet cafés, hostels, friends' laptops and the printer room machine that nobody has updated since last term. They are convenient and often necessary, especially when your own laptop is broken or you need expert software. They also carry risks, because the next user, or malicious software, can see what you leave behind. A short routine makes shared computers safe enough for most tasks, and tells you when to avoid them.

Policies and systems differ between institutions. This guide is general advice; follow your university's rules for lab and library use.

What can go wrong

• Leftover sessions. If you do not sign out, the next person can open your email, cloud files or learning platform.
• Saved passwords and autofill. Browsers may store credentials without you noticing.
• Keyloggers. Hardware or software that records what you type, installed by someone with access to the machine.
• Shoulder surfing. People watching you type passwords or read private messages.
• Leftover files. Downloads, printed documents, temporary files and browser caches.
• Malware. Shared machines may be less well protected, and infected USB drives are common.
• Fake login pages or tampered browsers.
• Public networks. Many shared computers use shared networks. See our public Wi-Fi safety guide.

Decide whether to use it

Use shared computers for low-risk tasks like reading, drafting a document you will save to the cloud, printing or using lab software. Avoid:

• Online banking and payments when you have a safer alternative.
• Entering passwords for sensitive accounts if you can use your own device.
• Accessing highly personal documents such as identity scans.
• Using your password manager unless necessary.
• Making major account changes.

If a task is sensitive and you must use a shared computer, plan extra steps below, and change passwords afterward from a trusted device.

Before you start

• Look for signs of tampering: strange devices on the keyboard cable, loose ports or unfamiliar software. Report anything suspicious to staff.
• Check that the computer is the one you should be using, and not a fake login screen.
• Use a guest or temporary profile if available.
• Open a private or incognito window so that history and cookies are not stored locally. Close all windows when you finish.
• Do not allow browsers to remember passwords or fill forms.
• Avoid installing software or extensions.
• Keep your belongings with you, and do not leave the machine unattended while signed in.

While you work

• Use official sites by typing addresses or using trusted bookmarks.
• Check the address bar before entering credentials.
• Cover your hands and screen when entering passwords or private messages.
• Use two-factor authentication. If a keylogger captures your password, a second factor reduces the harm. Do not select "remember this device."
• Avoid reading very personal messages in public spaces.
• Do not save files to the local desktop or documents folder. Save to cloud storage or a personal drive, and delete temporary copies.
• Be careful with downloads. If you must download a file, delete it afterward and empty the trash.
• Print carefully. Send jobs only when you can collect them, and take all pages. Use secure printing options if available.

USB drives and external media

• Prefer cloud sharing to USB drives. They can carry malware to or from the computer.
• If you use a USB drive, scan it for malware, and do not plug in unknown drives.
• Eject safely and take it with you.
• Avoid leaving files on the computer.
• Encrypt drives that hold sensitive information.
• Never plug your phone into unknown computers to charge unless it is set to charge-only. Use your own charger or a portable battery.

Signing out properly

Closing the window is not enough.

1. Log out of every account you used: email, learning platform, cloud, social media.
2. Close all browser windows, including private ones.
3. Clear history, cookies, cached files and downloads if you used a normal window.
4. Check the downloads folder and the desktop for files you created.
5. Empty the recycle bin or trash.
6. Sign out of the computer itself or restart it if allowed.
7. Take your belongings, including printouts and drives.
8. Do not leave notes with passwords on the desk.

If a login page remains open or the machine locks strangely, tell staff.

If you forgot to sign out

• Go back immediately if you are nearby.
• Otherwise, sign out remotely. From a trusted device, open your account security settings and sign out of all sessions or devices.
• Change your password, and any others you used on that machine.
• Check recent activity for anything unfamiliar.
• Tell your library or IT service so they can clear the machine.
• Enable two-factor authentication if you have not.

If you suspect a keylogger or compromise

Signs include unusual devices attached to the keyboard, strange behavior or warnings you did not expect. If you think a computer has been tampered with:

• Stop using it.
• Tell staff or IT immediately.
• Change passwords of any account you used, from a trusted device.
• Enable two-factor authentication.
• Check your accounts and bank statements for unusual activity.
• Run a security scan on your own devices if you connected them.

Using a friend's or a hostel's computer

• Ask permission and tell them what you are doing.
• Use a guest profile or private window.
• Avoid saving anything.
• Do not install software.
• Sign out of everything.
• Be careful about what you view on someone else's equipment.

For research, labs and licensed software

University labs may require login with your university account and may have monitoring. Do not install personal tools. Save work to your network drive or cloud, and follow acceptable-use policies. For group projects, avoid sharing passwords. Use shared folders with proper access.

Choosing the right place and time

Some shared computers are safer than others. Machines in staffed libraries or labs with logins tied to your university account are generally better managed than public internet terminals in hotels and cafés. Quiet times let you work without people watching your screen, and you can take care to clear the session properly. If you must use a public terminal, keep the session short, use private browsing and avoid entering your most sensitive passwords.

Teaching others in your group

If you work in a study group, agree rules for shared machines. Do not share your login. Use shared cloud folders with proper permissions instead of one person's account. Make sure the last person leaving signs out and clears the session. Remind newer students to avoid saving passwords in the browser. A group habit is easier to keep than a private one.

When you are not sure

If a machine seems strange, an unfamiliar window appears or the login behaves oddly, stop and ask staff. It costs nothing to switch to another computer or to use your phone for a quick task. Being a little cautious is better than spending a weekend recovering accounts.

Keep a small checklist on your phone with the sign-out steps, so you can run through it quickly at the end of any session on a machine you do not own.

Take your time with each of these steps, and do not worry about doing everything in a single day. Steady progress, repeated over a few weeks, builds habits that last well beyond your degree and carry into your working life.

Common mistakes

• Not signing out.
• Letting the browser save passwords.
• Using sensitive accounts on shared machines.
• Saving files to the desktop.
• Plugging in unknown USB drives.
• Leaving printouts behind.
• Ignoring signs of tampering.

A quick checklist

• Do I really need to use this computer for this task?
• Am I using a private window or guest profile?
• Have I avoided saved passwords and autofill?
• Did I sign out of everything and clear my files?
• Do I know what to do if I forgot to sign out?

Final thoughts

Shared computers are fine for everyday study tasks when you treat them as temporary and untrusted. Use a private window, avoid saving passwords and files, sign out completely and take everything with you. Keep sensitive tasks for your own devices, use two-factor authentication and act quickly if you slip up. A few seconds of care at the end of each session prevents long problems.