Ten things to check on a used laptop before you buy

What you can see in ten minutes

Pick the machine up and work through the list in order. Each point takes under a minute.

• Battery health. In Windows: open Command Prompt and type powercfg /batteryreport. The report shows the original capacity against the current one. Below 70 percent means a new battery is coming.
• The screen on a white and then a black background. Dead pixels show on white; backlight bleed and burn-in show on black.
• Every single key. Open a blank document and press through all of them. One dead key is cheap to live with, but it belongs in the price.
• Every port, with something in it. Bring a USB stick and an HDMI cable. Ports that were never tested are the most common unpleasant surprise.
• Disk health. CrystalDiskInfo reads the SMART data and tells you how long the disk has run and whether it is reporting errors.
• The fan under load. Open a handful of tabs and listen. A scraping sound is a bearing on its way out.
• Camera, microphone and speakers. Start a call with yourself in any app.
• The hinges. Open and close the screen slowly. Creaking or play ends up cracking the chassis.
• BIOS password and device locks. Restart and enter the BIOS. A machine locked by a previous owner cannot always be unlocked — not by us either.
• The Windows licence. Under Settings, System, Activation it should say that Windows is activated.

Ask two questions

Is the power supply included? And why is the machine being sold? The first is a real cost if the answer is no. The second rarely gets you a false answer if you ask straight out.

What a letter does not tell you

Sellers often write grade A or B. There is no shared standard for what the letters mean — two sellers can call the same machine different things. Ask for the condition described in words.