7 Tests to Run Before Buying a Used Windows PC or Laptop

Purchasing a used computer can be a smart choice if you're on a limited budget. While a discounted Windows device may seem tempting, it's important to proceed with caution and run a few essential tests to avoid unexpected issues down the line.

1 Test Display, Keyboard, and Trackpad

The display, keyboard, and trackpad are among the most critical components to inspect when buying a used laptop. These parts are essential for daily use, and any issues can significantly impact the device's usability.

To test the display, visit a website like Test My Screen and check for dead pixels, discoloration, or flickering. You can use solid-colored backgrounds (white, black, red, green, and blue) to spot pixel irregularities. Additionally, try adjusting the brightness to ensure it functions properly and check for backlight bleeding or uneven lighting.

For the keyboard, use an online tool such as Keyboard Tester to confirm that all keys are responsive. To test the trackpad, simply move the cursor to ensure smooth tracking and try multi-touch gestures like scrolling, pinch-to-zoom, and multi-finger tapping, if supported. Additionally, check that the physical click buttons (left and right) respond well and aren't stuck or overly stiff.

2 Test Webcam, Microphone, and Speakers

If you're buying a laptop, testing the webcam is important. You can do this by simply opening the built-in Camera app on Windows. You should see a clear, functioning image. If the camera is blurry or unresponsive, it could indicate an issue.

Next, test the microphone by going to Settings > System > Sound. Under the Input section, select the built-in microphone device, then click Start test. Begin speaking, then use the Play button to listen to the recorded audio and check for clarity, distortion, or volume issues.

For the speakers, return to the Sound menu, go to the Output section, and select the built-in speakers. Click the Test button to play a sound and ensure the audio is clear without crackling or distortion.

In addition to the above, it's important to test your laptop or PC's ports, such as HDMI, USB, the 3.5mm headphone jack, and others. You'll want to plug in various devices like a USB drive, headphones, or an external display to confirm that each port is responsive and works as expected.

3 Test the RAM

A RAM malfunction occurs when a process writes data to RAM, but RAM returns different data when retrieving the same information. If you buy a computer with faulty RAM, you'll likely encounter crashes, distorted graphics, sluggish performance, and endless errors.

Hence, testing the RAM before purchasing a used PC is crucial. While various third-party tools are available to test RAM, we recommend using the Windows Memory Diagnostic tool. Before running the test, save any unsaved progress, as the tool will require your computer to restart.

1. Press Win + R to open the Run dialog box.
2. Type mdsched in the text box and hit Enter.
3. Click on Restart now and check for problems (recommended).

After following the above instructions, Windows will restart once, and the Memory Diagnostic tool will begin running after booting. Once the test is complete, Windows will restart again.

Upon the second restart, you may see the test results immediately, or you may need to open the Windows Event Viewer to find them.

1. Right-click on the Windows Start button and go to the Event Viewer.
2. Go to Windows Logs and navigate to System.
3. Click on Find under Actions in the right-hand pane.
4. Type MemoryDiagnostic and click on Find Next.

   

Wait for the Event Viewer to search for the string in its data and show the test run result.

4 Check the Health of Your Hard Drives

Typically, computer hard drives, whether SSDs or HDDs, are designed to last a long time and rarely fail. However, it's crucial to ensure their health is in good condition, their temperature stays within an acceptable range, and they don't have bad sectors or blocks.

A faulty hard drive can lead to various issues, such as the inability to read from or write to the drive, frequent computer crashes, slow file loading, and other problems.

You can check the health of your hard drives using a tool like CrystalDiskInfo. Download and run the CrystalDiskInfo tool on your computer, and you'll see the statistics of all the drives on your computer. If you have more than one hard drive, you can switch between them by clicking on the arrow button in the top-right corner.

From all the stats the tool shows you, the health status and temperature are of the utmost importance. Your hard drive's health status should be Good, and its temperature should be between 30 °C and 50 °C. In the worst-case scenario, the temperature shouldn't go higher than 70 °C.

5 Test Battery Health

The charging capacity of laptop batteries declines over time. If the battery in the laptop you're considering buying has suffered significant wear, you may not get as much charge, and you might even need a replacement.

To avoid incurring this extra cost after the purchase, running a battery health check beforehand is important. Follow these steps to generate a battery report:

1. Open the Windows search menu and type cmd in the text box.
2. Right-click on the Command Prompt app and click Run as administrator.
3. In the console, type powercfg/batteryreport and hit Enter.

The above process will generate a battery report and save it to a specific folder, which in most cases would be C:\Users\[UserName]\battery-report.

Analyze the battery usage and life estimates by thoroughly inspecting the battery report. You should ensure that the estimated battery life after a full charge is adequate. If the battery needs to be replaced, factor that cost into your decision when purchasing a used laptop.

You can also check the battery health using different battery health tools for more in-depth analysis.

6 Stress Test the CPU and GPU

Another important step is to ensure that the CPU and GPU are powerful enough to handle the tasks you plan to assign them. The best way to determine their capability is to stress-test both components.

A stress test pushes the computer's hardware (CPU, GPU) to its maximum performance and monitors how well it handles extreme loads. If the PC remains stable during the stress test, you've made a good choice, as it indicates the system won't crash or malfunction under heavy loads.

If you need help with this, refer to our article on how to stress test CPU and GPU safely.

7 Keep the Temperature of the CPU and GPU Under-Check

When your computer shuts down during a stress test, it's because it's overheating at a critical temperature rather than being overburdened. If this happens, you can then decide whether you need an extra case fan, cooling kit, or anything else to keep the component's temperature at safe levels.

If you don't get the CPU and GPU temperature data during the stress test run, we recommend using dedicated software to keep their temperature in check.

NZXT's CAM software is highly recommended, as its intuitive interface makes it easy to adjust clock speeds and fan settings, while also allowing you to monitor the component's temperature under your preferred load.

Whether you're buying a decade-old PC or receiving a hand-me-down, running these tests will help you assess the condition of your computer's hardware. So, make sure to take the time to perform these simple checks to ensure you're investing in a reliable, fully functional device.