Yellow warning in Device Manager
Why does Device Manager show a yellow exclamation mark?
Written by The CommonFixes team · fact checked by CommonFixes review desk
Last updated
Short answer
That triangle means Windows can see a piece of hardware but cannot use it properly, nearly always because the right driver is missing, damaged or the wrong version. Each one carries a numbered code that tells you exactly what went wrong, and reading that code saves you from trying random fixes. Code 28 means no driver installed, code 43 means the device reported a fault, code 10 means the driver would not start, and code 31 means the driver is there but broken. The quickest thing to try first: read the code before doing anything — Right click Start, open Device Manager, double click the item with the triangle and look at the Device status box on the General tab. Write down the code number. Everything you do next depends on it, and it turns a vague warning into a specific problem. Most people are done in about 20 minutes.
Full walkthrough below: 7 steps for Windows, rated medium.
Sounds like this
- •A little yellow triangle sits next to one item in Device Manager
- •The device it names does not work at all
- •Sometimes it is listed as Unknown device or Other devices
Why it happens
That triangle means Windows can see a piece of hardware but cannot use it properly, nearly always because the right driver is missing, damaged or the wrong version. Each one carries a numbered code that tells you exactly what went wrong, and reading that code saves you from trying random fixes. Code 28 means no driver installed, code 43 means the device reported a fault, code 10 means the driver would not start, and code 31 means the driver is there but broken.
Work through these in order
0% done- 1
Read the code before doing anything
Right click Start, open Device Manager, double click the item with the triangle and look at the Device status box on the General tab. Write down the code number. Everything you do next depends on it, and it turns a vague warning into a specific problem.
- 2
Get the correct driver from the laptop maker
For codes 28 and 31, go to the support page for your exact model and serial number on the Dell, HP, Lenovo, Asus or Acer site and download the driver for that device. This beats Update driver in Windows every time, because Windows only offers generic drivers and often has nothing at all for chipset, card reader and fingerprint hardware.
- 3
Identify an unknown device before you hunt for a driver
If it just says Unknown device, open its Properties, the Details tab, and choose Hardware Ids from the drop down. Search the VEN and DEV numbers on the web and you will find what the part actually is. There is no point installing drivers at random.
- 4
Remove and let Windows redetect it
For code 10 and code 43, right click the device, choose Uninstall device, tick Delete the driver software for this device if it is offered, then restart. Windows reinstalls it cleanly on the way back up. This clears a driver that got corrupted by a failed update.
- 5
Unplug the power completely for a USB device showing code 43
Shut down, unplug the charger, and on a laptop with a removable battery take it out. Hold the power button for thirty seconds, then start again. This clears the USB controller state, which is what code 43 on a USB device usually needs rather than a driver at all.
- 6
Repair the system files if several devices are flagged
Right click Start, choose Terminal (Admin) and run sfc /scannow, then DISM /Online /Cleanup-Image /RestoreHealth, then restart. When more than one device breaks at the same time, the driver store itself is usually damaged rather than each device.
- 7
Check the BIOS if the device has vanished entirely
Restart and press the setup key for your machine, usually F2, F10 or Delete. Confirm the part, for example the Wi-Fi card or the fingerprint reader, is turned on. Some maker updates disable hardware, and no driver will help while the BIOS has it switched off.
If none of that worked
If the same device fails with code 43 after a clean driver install and a power drain, the hardware itself is failing. On a laptop, a Wi-Fi or Bluetooth card is a cheap part for a workshop to swap; on a desktop, try the card in a different slot to confirm before buying anything.
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Who wrote this and how we checked it
The CommonFixes team
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We are a small group of people who spend our days repairing laptops and desktops for family, friends and small offices. Every guide here starts with a problem someone actually brought to us, and we only write down the steps that put the machine right.
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CommonFixes review desk
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This guide was last updated on 10 August 2026. If a step no longer matches what you see on screen, tell us on the contact page and we will test it again.
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