Ethan Brooks
How To Detect Unauthorized Access on Your PC
If the thought of someone sneaking into your computer without permission keeps you awake at night, you’re not alone. Whether it’s a shared laptop or a work computer, spotting unauthorized logins or suspicious activity is crucial to keeping your data safe. Windows has built-in tools like Event Viewer that can help you peek into recent login history and system activity—no extra software needed. That said, kind of weird how Windows hides this stuff sometimes, but if you know where to look, it’s doable. By digging into logs and recent files, you’ll get a better idea of what’s been happening behind your back.
How to Check for Unauthorized Access in Windows
Open the Event Viewer
This is the main place to see login events, system alerts, and security info. Not gonna lie, finding this tool can be a little confusing at first because Windows always throws it somewhere between “hidden gem” and “where did they hide that?” Mainly, you wanna open Event Viewer to see security logs where logins get recorded.
- Right-click on the Start button or press Windows key + X.
- Click on Run. If you prefer, you can type
eventvwrdirectly into the search bar, but right-click + run is easier if you already have the context menu. - Type
eventvwrinto the Run box and hit OK. This opens the Event Viewer window. Sometimes, it takes a second or two to load, so be patient.
Note: On some setups, this may require admin permissions, so make sure you run it as admin (right-click > Run as administrator).
Navigate to Security Logs
Once inside Event Viewer, it’s all about the security logs—they record security-related events like logins. Windows logs these under Windows Logs > Security. That’s the hidden treasure here.
- In the left pane, expand Windows Logs, which is usually near the bottom.
- Click on Security. Here, you’ll start seeing a jumble of events, mostly coded and long-winded, but you’re looking for login info.
Note: If you want to make this more manageable, you can filter the current log for specific event IDs related to logon events (more on that in a sec).
Check for Logon Events
This part is a bit like detective work. You’re looking for events that indicate someone has signed into the PC. Windows logs these as specific event IDs, and on one setup it worked, on another—less so, but here’s the gist.
- Look for entries with Event ID 4624 — that indicates a successful logon. If you see unfamiliar times or user accounts, that’s suspicious.
- Double-click on some of these events to see the details, like the Account Name, Logon Type, and Network Information. This will tell you if someone logged in locally or remotely, which can clue you in on whether it’s legit or not.
Tip: To narrow down the entries, you can apply a filter and input 4624 as the event ID. Also, on some machines, the first few logs might be empty or incomplete; it’s kind of normal. On others, you might need to dig through a lot of noise.
Review Recent Files and Activity
If you’re wondering whether someone’s hacked your files or opened stuff without permission, Windows’ Recent Items folder can be a clue. Not foolproof, but helps to spot recent access patterns.
- Right-click the Start button and select Run, or press Windows key + R.
- Type
recentand press Enter. This opens up the folder with your recent files.
From here, you can see which documents or images were opened, helping you spot if files you didn’t touch show up or get modified. If you suspect someone accessed your files remotely, cross-reference timestamps or look for unusual file access times.
Pro tip: For a more detailed file history, you might consider setting up Windows File History or third-party tools later on—because of course, Windows has to make it harder than necessary.
Extra Tips & Common Troubleshooting
In case things feel fuzzy or logs aren’t clear, here are some quick ideas:
- Regularly change your password, especially if you see any questionable activity. Use a strong passphrase—no “password123” kind of stuff.
- Turn on two-factor authentication if your accounts support it. Adds a layer of security, even if your password leaks.
- Set up a standard user account rather than an admin one for daily use — less damage if it gets compromised.
- Keep your OS and software updated — that bugs, vulnerabilities, and malware won’t patch themselves.
Wrap-up
Getting a handle on who’s been poking around your Windows PC isn’t foolproof, but looking into Event Viewer and recent files gives you a decent shot at catching the unwelcome guest. Just be aware that some of this is more trial and error—because Windows doesn’t exactly make security logs front and center.
Summary
- Open Event Viewer with
eventvwr - Check Security logs for Event ID 4624 (logins)
- Review recent files using the recent folder
- Adjust security settings, change passwords, and keep your system up to date
Fingers crossed this helps
Honestly, finding sneaky logins or suspicious activity can be a bit of a pain, but once you get the hang of the logs, it’s kinda satisfying. Sometimes, suspicious activities pop up and turn out to be totally legit, but better safe than sorry. Hope this gives a decent starting point for spotting unauthorized access. Just something that worked on multiple machines, and hopefully it does on yours too.