Windows ERROR_INSUFFICIENT_POWER (0x0000027F) fix for USB and PCI devices
Your USB or PCI device error 0x0000027F means Windows sees the port can't supply enough power. Try plugging into a powered hub or disabling selective suspend.
When you see error 0x0000027F
You plug in a USB 3.0 external hard drive, a PCIe capture card, or a wireless adapter — and Windows pops up: "There is not enough power to complete the requested operation" with error code 0X0000027F. This usually happens right when you connect the device, not after a few minutes. I've seen it most often with bus-powered external drives and high-draw USB Wi-Fi adapters on laptops with weak power delivery.
What's actually happening
Windows is telling you the USB port or PCIe slot can't deliver enough electrical current to run the device you plugged in. The motherboard's voltage regulator detected a voltage drop and shut down the port to protect your hardware. It's not a driver issue — it's a power budget issue. On many laptops, USB ports share a single power rail, and if your device tries to draw more than 0.5A (USB 2.0) or 0.9A (USB 3.0), you get this error.
Step-by-step fix
Skip the driver reinstall — that won't fix this. Here's what actually works.
Step 1: Use a powered USB hub
This is the #1 fix. Grab a USB hub that plugs into the wall (not just the USB port). Plug your device into the hub, not the laptop. The hub supplies its own power, so your device gets clean current. I use an Anker 4-port powered hub for my external SSD — haven't seen this error since.
Step 2: Disable USB selective suspend
Windows sometimes puts USB ports into a low-power state to save battery, but this can drop voltage enough to trigger the error. Turn it off:
- Press Win + R, type
powercfg.cpl, hit Enter. - Click "Change plan settings" next to your active power plan.
- Click "Change advanced power settings".
- Scroll to USB settings > USB selective suspend setting and set it to Disabled.
- Click Apply, then OK.
Step 3: Update USB controller drivers
Old drivers can misreport the power capability. Head to Device Manager (right-click Start > Device Manager), expand Universal Serial Bus controllers, right-click each USB Root Hub and Generic USB Hub, choose "Update driver" > "Search automatically". Reboot after.
Step 4: For PCIe devices — increase PCIe power
If you're getting this error on a PCIe card (like a sound card or Wi-Fi adapter), the PCIe slot might be stuck in a power-saving mode. Go to BIOS (restart and mash F2 or Del), look for PCI Express Power Management or ASPM, set it to Off or Performance. Save and exit.
If it still fails
Check your device's power specs. A bus-powered USB 3.0 hard drive often needs 1.5A, but a port might only deliver 0.9A. The real fix is a powered hub. For laptops, also run this command as admin to force the USB ports to stay active:
powercfg /setacvalueindex SCHEME_CURRENT SUB_USB USB_SEL 0If you're on a desktop with this error on the rear USB ports, try the front USB ports — those are sometimes on a separate power rail with better specs. Still broken? The device itself could be faulty; test it on another PC.
One last thing
I've seen people replace motherboards over this error. Don't. It's almost always a power budget mismatch, not a hardware failure. A $15 powered hub or flipping a BIOS setting is all you need.
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