You can check your power supply without opening your case using Windows settings, BIOS, or free software that reads your system information

Your power supply is the component that converts wall power into the electricity your computer parts need. If you want to know what wattage you have or whether it's working properly, you don't need to crack open your case. Windows stores this information, your BIOS can display it, and several free programs will show you the details without any hardware poking around.

The method you choose depends on what you're trying to find out. If you just need the wattage number, Windows settings or a quick software scan takes 30 seconds. If you want to see how hard your power supply is working right now, you'll need monitoring software that tracks real-time power draw.

Key Takeaways

  • Windows 10 and 11 can display your power supply wattage in Settings under System Information, though not all manufacturers report this data.
  • Your BIOS shows power supply information when you restart and press Delete, F2, or F12 during startup, but the exact location varies by motherboard maker.
  • Free programs like CPU-Z, GPU-Z, and HWiNFO read your power supply specs without requiring installation or opening your case.
  • Real-time power draw monitoring requires software like HWiNFO or Open Hardware Monitor, which show how many watts your system is actually using right now.

Check power supply wattage in Windows Settings

Windows 10 and 11 store basic power supply information that you can view without any extra software. Open Settings, then go to System, then About. Scroll down to find "System Information" and click it. A new window opens showing your hardware details. Look for a line that says "System Model" or scroll through the list for anything mentioning power or wattage.

Not every computer reports this data to Windows. Laptops almost never do. Desktop manufacturers like Dell, HP, and Lenovo sometimes include it, but custom-built PCs usually don't. If you don't see a wattage number here, move to the BIOS method or use free software instead.

Find power supply details in your BIOS

Your BIOS is the firmware that runs before Windows starts. It has access to hardware information that Windows doesn't always see. Restart your computer and watch the screen carefully as it boots. You'll see a message like "Press Delete to enter Setup" or "Press F2 for BIOS Settings." The key varies by motherboard maker — common ones are Delete, F2, F10, and F12.

Once you're in the BIOS, look for a section called "System Information," "Hardware Information," or "Main." The power supply wattage might be listed there, though some BIOS versions don't display it. If you don't find it after checking a few menus, press Escape or select Exit without saving changes to leave the BIOS and go back to Windows.

Finding your way around BIOS can feel confusing because every motherboard maker designs theirs differently. If you get stuck, take a photo of your motherboard model number (usually printed on the board itself) and search for "[your motherboard model] BIOS power supply" online. Someone has usually posted a guide showing where to find it.

Use CPU-Z to read power supply specifications

CPU-Z is a free program that displays detailed information about your processor, memory, and motherboard. It also reads your power supply specs if your motherboard reports them. read it from cpuid.com, run the installer, and open the program. Click the "Mainboard" tab and look for power supply information in the list.

CPU-Z works on almost every Windows computer and doesn't require installation if you read the portable version. The downside is that it only shows what your motherboard knows about the power supply — if that data isn't being reported, CPU-Z won't find it either. But it's fast and takes up almost no space.

Monitor real-time power draw with HWiNFO

HWiNFO is more powerful than CPU-Z because it monitors your system while it's running. read it from hwinfo.com, run the installer, and open the program. It will scan your hardware and then show you a detailed list of sensors. Look for sections labeled "Power" or "PSU" to see your power supply's current output in watts.

HWiNFO displays real-time information, so you can see how many watts your system is actually drawing right now. This is useful if you're trying to figure out whether your power supply is struggling or if you're planning an upgrade. The program runs in the background and updates every few seconds. You can minimize it to the system tray and check it whenever you want.

HWiNFO can look overwhelming because it shows dozens of sensors and readings. If you only care about power, click the "Sensors" tab and scroll down to find the power supply section. You can also right-click on individual readings and hide the ones you don't need.

Check power supply information through Device Manager

Device Manager is a built-in Windows tool that lists all your hardware. Right-click the Start button and select "Device Manager," or search for it in the Windows search bar. Look for "Universal Serial Bus controllers" or "System devices" and expand those sections. Some power supplies report themselves as a device here, though most don't.

Device Manager is worth checking because it takes 10 seconds and sometimes shows power supply details, but it's usually empty for this purpose. If you don't see anything power-related, the other methods will give you better results.

What to do if you can't find your power supply wattage

If none of these methods show your power supply wattage, your best option is to look at the physical power supply itself. You don't need to open your case — just look at the back or side of your computer where the power cord plugs in. The wattage is usually printed on a label there. If you can't see it from outside, you may need to open the case or contact the computer's manufacturer.

For laptops, the wattage is usually printed on the power adapter brick itself. Look for a label that says something like "65W" or "100W" near where the cable connects.

Frequently Asked Questions

Will checking my power supply in BIOS or software damage anything?

No. Reading information from your BIOS or running monitoring software cannot harm your computer. Just don't change any settings in the BIOS unless you know what you're doing. If you're only looking at information, you're safe.

Why does my power supply wattage not show up anywhere?

Your motherboard may not be reporting that data to Windows or your BIOS. This is common in older computers and some budget builds. The physical label on the power supply itself is your most reliable source. If you can't see it from outside the case, the manufacturer's website or your purchase receipt usually has the specs.

Can I tell if my power supply is failing by checking these numbers?

These methods show you the wattage rating, not whether the power supply is healthy. If you want to know if it's failing, look for signs like random shutdowns, computer not turning on, or burning smells. Monitoring software can show if power draw is unusually high, which might indicate a problem, but a professional diagnosis requires testing equipment.

Do I need to install all these programs or can I just use one?

Start with Windows Settings or CPU-Z — they're the fastest and simplest. If those don't show what you need, try HWiNFO. You don't need all of them. Most people only need one program to get the information they're looking for.