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How to check a used laptop before you buy it

Updated September 26, 2026

A used laptop has plenty of parts that wear out: a tired battery, dead keys, loose hinges, clogged fans, an ageing SSD. Many problems only appear after weeks of use, so a careful check at purchase is the cheapest way to avoid repair bills. Bring the laptop's charger, a mouse or USB stick, and allow 20–30 minutes.

Tip: open soimay.com in Chrome or Edge on the laptop itself; nothing needs installing. This guide is for Windows laptops; buying a MacBook? See also how to check a used MacBook.

1. Do the specs match the listing?

The seller says Core i7, 16 GB of RAM, a 512 GB SSD? Check for yourself:

  • Press Ctrl + Shift + Esc to open Task Manager and go to the Performance tab for the CPU name, RAM, drive and GPU.
  • Settings › System › About shows the device name, CPU, RAM and Windows edition.
  • Compare the model name with the label under the laptop and the maker's website.
Check device specsSee the model, operating system, CPU threads, GPU, RAM and screen resolution of a phone or laptop in the browser, and compare them with what the seller claims.

2. Windows activation, BIOS password

  • Settings › System › Activation must say Windows is activated.
  • Restart into the BIOS (usually F2, F10, F12 or Del): there must be no BIOS password. A BIOS-locked laptop, especially an ex-corporate one, is very hard to unlock.

3. Screen

Fill the screen with each colour to find dead pixels, backlight bleed at the edges (black screen, dim the room) and yellow stains (white screen). Open and close the lid a few times and watch for flicker or lines as the angle changes: a sign of a failing display cable.

Dead pixel, backlight bleed and burn-in testFind dead or stuck pixels, backlight bleed, burn-in and lines on a phone or laptop screen. Eight full-screen colours, free, no app to install.

If it is sold as 120 Hz or 144 Hz, also measure the refresh rate while plugged in.

4. Keyboard

Press every key in turn, including F1–F12, the arrows and the number pad (if any). A key that doesn't light up is dead; one that stays lit is stuck. Keyboard lock mode in Chrome and Edge can test F11, Esc and the Windows key too.

Laptop keyboard testPress every key to find dead or stuck keys on a Windows laptop or MacBook. Blocks F5 and F12, with a keyboard-lock mode to test F11, Esc and the Windows key too.

Toggle the keyboard backlight (if any) and try the Fn shortcuts such as volume and brightness.

5. Touchpad

Left click, right click, double click, two-finger scroll, pinch to zoom, and move the cursor across the whole pad. A cursor that jumps or stutters usually means a faulty touchpad or a swollen battery pushing it up from below.

Touchpad and mouse testTest a laptop touchpad or mouse: left, right and double click, vertical and horizontal scroll, pinch to zoom, and a cursor that doesn't jump.

6. Battery

Open Command Prompt, type powercfg /batteryreport and open the battery-report.html it creates. Compare:

  • Design Capacity: the capacity when new.
  • Full Charge Capacity: the capacity now.

Over 80% is good, 60–80% is worn (usable, but worth a lower price), under 60% needs replacing soon. More in how to check battery health.

7. SSD health

Get the portable version of CrystalDiskInfo (no install needed): Health Status must be "Good". Also look at Total Host Writes and Power On Hours to see how heavily it has been used.

8. Temperature and fans

Run the CPU test for about 25 seconds. The fan should spin up without rattling or grinding. If performance drops sharply during the run or the bottom gets too hot to touch, it needs cleaning and fresh thermal paste: not a big fault, but a reason to negotiate.

CPU test: performance and overheatingScore single-core and multi-core CPU performance and run a 20-second heavy load to catch overheating and throttling from dried thermal paste, dusty fans or a weak battery.

9. Webcam, speakers, microphone

Open the camera to see if the picture is sharp, play the speakers left and right and sweep for crackling, and record with the microphone test. For video calls all three matter.

10. Ports

Try every port: USB-A, USB-C, HDMI, card reader, headphone jack. If it charges over USB-C, try that too. Plug in the charger and wiggle the plug gently: a charging light that flickers means a loose charging port.

11. Hinges, body, screws

Open and close the lid many times: the hinges should be firm and smooth, and the screen shouldn't wobble while you type. Check the bottom screws are all there and not stripped, and look for cracks around the hinges. A bulging case or raised touchpad is a sign of a swollen battery, which needs replacing right away.

12. WiFi and Bluetooth

Connect to WiFi and test the speed in the same spot as your phone to compare. Pair a Bluetooth mouse or headphones.

Save the results

The soimay.com Results page lets you save a PDF or create a report link. Things to check by hand (battery, SSD, BIOS, ports) are in the manual checklist.

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