How to Check Your PC’s Power Supply (Windows 10 and 11)

To check a desktop PC’s power supply, identify the installed unit from its label or the computer maker’s exact configuration record. Windows 10 and Windows 11 usually cannot show a standard power supply’s model, rated wattage, or health. A battery report is for a laptop battery; it does not test a desktop power supply.

Start with the question you need answered. Finding which power supply you own, measuring electricity use, and diagnosing a faulty unit require different evidence.

Choose the right check

You want to know	Start here	What the result means
Brand, model, and rated watts	Purchase record, exact manufacturer configuration, or PSU label	Identifies the hardware; does not prove it is healthy
Why the PC loses power	External cable and outlet checks, then the model’s service diagnostics	Helps narrow the cause; a restart alone is not a diagnosis
How much electricity the PC uses	A suitable plug-in power meter	Measures input at the wall; does not reveal the PSU’s maximum output
Why a laptop battery lasts less time	A Windows battery report	Shows battery usage and capacity information, not desktop PSU health

PSU means power supply unit, the component that supplies power to your desktop’s hardware. In many towers it is a metal box near the rear, with the mains power cable connected outside the case. Some small desktops and all-in-one computers instead use an external adapter.

Find the power supply without opening the computer

Try this first if you have a factory-built computer, cannot reach the label, or prefer not to remove a case panel.

1. Find the computer’s exact model and configuration. Read the case sticker, service tag, original receipt, or order confirmation. A family name alone may cover several different power supplies.
2. Open the manufacturer’s support website. Look up that model or service tag, then open its specifications, original configuration, or service manual. Check the section for the power supply and record the listed wattage and part number.
3. Check your purchase history. For a custom build, look for the separately purchased PSU on the parts invoice. A product listing for the case or motherboard does not identify it.
4. Account for replacements. If the PC has been upgraded or repaired, its original specification may no longer match the installed unit. Verify the current label or ask the repairer which part was fitted.

If you need help identifying the computer, Microsoft documents the System Information tool. Search Start for System Information or msinfo32. Its system summary can help with the computer lookup, but is not a reliable inventory of a standard desktop PSU. For the parts Windows can report, see how to check system configuration in Windows 11.

A support page that offers both a 300 W and a 500 W option does not establish which one you have. Record the uncertainty instead of choosing the larger number.

Read the installed PSU’s label

Keep the PSU itself closed. Removing a computer’s side panel is different from opening the power supply’s metal housing. Corsair warns against opening a PSU because dangerous charge can remain after it is unplugged. Pressing the computer’s power button does not make the PSU’s internals safe to touch.

Use your computer’s service manual for the case-panel procedure and precautions. If that procedure is unfamiliar, or the unit is sealed or difficult to access, use the manufacturer lookup or a repair technician instead.

1. Save your work and shut down Windows. Choose Start > Power > Shut down. Wait for the computer to finish shutting down.
2. Disconnect mains power. Switch the PSU off if it has an on/off switch, then unplug the power cable. Follow the computer maker’s instructions for disconnecting accessories and handling the case.
3. Remove only the permitted case panel. Follow the service manual rather than guessing which screws to undo. Locate the PSU without unplugging internal connectors or removing the PSU housing.
4. Read or photograph the accessible label. Look for the manufacturer, model or part number, and total rated output in watts. If a cover or the label’s orientation blocks the view, stop rather than dismantling unfamiliar parts.
5. Write down the exact details and close the case. Replace the panel as the manual directs before reconnecting power and turning on the PC. Keep a private copy of the label photo for future upgrades.

For example, suppose an old invoice lists “500 W PSU,” but the installed unit’s label identifies a different 650 W model. The label describes the current hardware; the invoice describes the earlier purchase. Neither tells you how many watts the computer is using right now.

Read the total output rating. Do not add every separate voltage-rail limit: combined limits can apply. Likewise, an AC input range such as 100–240 V is not a wattage rating, and an efficiency badge is not a health certificate.

If you suspect the power supply is faulty

Stop using the computer if you notice smoke, a burning smell, damaged insulation, or scorched connectors. Arrange service rather than deliberately running a heavy workload to reproduce the fault.

1. Check the external connections. With the computer off, inspect the accessible power cord for damage and check that it is properly connected. Do not reuse a damaged cord.
2. Rule out the power source. Check a known working outlet and any switched power strip. If safe and appropriate for the setup, test the PC directly from a working outlet. Leave voltage-selector switches alone unless the service manual explicitly requires a change.
3. Record what happens. Note whether there are no lights, fans but no picture, a blue screen, or a sudden restart during a particular task. These are different symptoms and can have different causes.
4. Use model-specific diagnostics. Some Dell desktops have a PSU built-in self-test, or BIST. Follow Dell’s self-test instructions for the correct model and button arrangement. An ordinary on/off switch is not a self-test button.
5. Escalate persistent problems. Give the technician the exact PSU model, symptoms, and diagnostic results. Check the manufacturer’s warranty or replacement process before purchasing a part.

A stationary fan does not automatically mean a dead PSU. Some supplies use a zero-RPM mode at light load. Conversely, a fan that spins does not prove the unit will work reliably under load. Corsair’s PSU testing documentation explains model-dependent fan behavior and external tests.

Paperclip jumpers, multimeters, and dedicated PSU testers are electrical tests, not Windows features. A startup test has limited diagnostic value; connecting the wrong pins can cause injury or damage. Have a technician perform those checks if you are unfamiliar with the equipment. Never use a generic pin diagram for an unknown or proprietary connector.

What Windows and monitoring software can tell you

Windows logs can help you match an unexpected restart to a time and error. They cannot, by themselves, prove that the power supply failed. Microsoft’s Event ID 41 documentation explains that an unclean shutdown can result from several causes, including power interruption or a stop error.

If you are diagnosing a Windows 11 restart, see our guide to checking crash logs with Reliability Monitor and Event Viewer. Match entries to the incident rather than treating every error as evidence of a faulty PSU.

Task Manager is not a desktop PSU tester. There is no general PSU-health “Power” section under Performance or Details that reports the unit’s rated output. CPU or GPU power readings in monitoring tools cover the reported components, not necessarily the entire computer or the PSU’s capacity.

There are exceptions for supported digital power supplies with their own data connection and vendor software. For example, Corsair documents PSU monitoring in iCUE. That requires compatible hardware; installing the application cannot add monitoring support to every PSU.

If you meant the laptop battery or charger

For an external adapter, identify the exact part from its label and the computer’s specifications. A charger that fits physically is not necessarily compatible. USB-C charging can also depend on the adapter, cable, port, and supported power profiles.

For battery information, Windows can create an HTML report:

1. Search Start for Command Prompt, right-click it, and select Run as administrator. Approve the permission prompt if you have permission to do so.
2. Enter powercfg /batteryreport and press Enter. Note the report location printed in the window.
3. Open that folder in File Explorer, then open the HTML report in your browser. Review battery usage and capacity information.

Microsoft’s powercfg documentation identifies /batteryreport as a battery report and /energy as an energy-efficiency analysis. Neither certifies a desktop PSU’s electrical health. A desktop without a battery will not gain useful battery-capacity information from this command.

Frequently asked questions

Can I check the PSU in BIOS or Device Manager?

Do not expect either to identify a standard PSU or certify its health. Some hardware exposes sensor readings or vendor diagnostics, but availability varies. Use the installed unit’s label and its manufacturer’s instructions.

Does the same approach work in Windows 11?

Yes. Reading the hardware label and checking the exact configuration are independent of Windows. The software exceptions still depend on compatible PSU hardware.

Can a power meter tell me which PSU I have?

No. A meter at the outlet measures electricity entering the computer. Rated PSU output, component demand, and wall input are different quantities. A reading below the label’s wattage does not establish that an upgrade is compatible.

What should I check before replacing the PSU?

Confirm the case dimensions, motherboard and graphics-card connectors, the new hardware’s requirements, and any manufacturer restrictions. Use cables approved for the exact replacement PSU. Modular cables are not universally interchangeable even when plugs look alike; Corsair’s installation and safety manual warns about incompatible cables.

Your next step is to record the installed model and rated output, then use the diagnostic procedure for that exact hardware if you are troubleshooting. Keep identity, electricity use, and health checks separate so a Windows report does not give you false reassurance.