Keep your PC healthy.

WinDiag is a free app for Windows 10 and 11. It checks your PC in one click, tells you what it finds in plain words and helps you fix it.

Download for Windows

Version 3.0.0 · 113 MB · Free and open source

Checkup

Your PC is fine, with 3 things worth a look.

5 good · 3 worth a look

  • ProtectionMicrosoft Defender is on and up to date, and the firewall is on.
  • Windows updates2 updates are waiting to be installed.Open Windows Update
  • Drive healthYour main drive is healthy.
  • Free space182 GB free of 476 GB on C:.
  • BatteryIt holds 87 % of the charge it held when new.
  • Startup apps9 apps start with Windows, which slows down startup.Manage startup apps
  • ActivationWindows is activated.
  • Last restartYour PC hasn’t restarted in 12 days. A restart finishes updates and frees up memory.

  • One app for the whole PC.

    Everything WinDiag 3.0.0 does, one key each. Keep scrolling.
  • 8checks, each with a plain verdict
  • Speed upStartup apps, free space, power mode
  • PrivacyWhat Windows shares, switched in one place
  • PersonalizeDark mode, taskbar, File Explorer
  • 45trusted apps, installed with winget
  • UpdatesWindows, drivers and BIOS
  • SecurityAntivirus, firewall, encryption, TPM
  • RepairThe fixes a technician tries first
  • HardwareKeyboard, screen, sound, battery, gamepad
  • 0 €No ads, no account, no trial

Press any key.

This is WinDiag’s keyboard test, right here. Every key you press shows up on the big key; in the app, the keys that never light up are the ones to fix.

0 of 27 keys tested

The real app.

When something is wrong, Repair has the safe fixes and Hardware tests each part of the PC, from the keys to the gamepad.

WinDiag’s Hardware page with eight tests: gamepad, keyboard and mouse, screen, touch, sound and camera, battery, drive health and USB ports
HardwareEight tests, one for each part of the PC.
WinDiag’s Repair page: restart File Explorer, clear the DNS cache, reset the Microsoft Store cache and repair system files
RepairEach fix says when to use it, how long it takes and whether it asks for permission.
WinDiag’s keyboard test: a full keyboard where every pressed key lights up
Keyboard & mouseEvery key and button, matched by position, so any keyboard language works.
WinDiag’s display test with white, black, red, green, blue and grey screens
ScreenFull-screen colours that show dead pixels, bleeding and uneven backlight.
WinDiag’s gamepad test asking you to press any button on your controller
GamepadFinds drift, dead buttons and worn triggers, and says why a controller isn’t seen.

Nothing changes without you.

The Repair page, where every fix waits for you to press Run

It asks first

WinDiag opens without administrator rights. Windows asks for your permission only when an action needs it, and drivers get a restore point first, so you can always go back.

Open, and only yours

Free and open source under the MIT licence. No account, no ads and no tracking: it only talks to Windows Update, winget and your PC maker’s site when you use them.

Read the code

Questions.

Is it really free?

Yes. WinDiag is free and open source under the MIT licence. There is no trial, no paid version of these features, no ads and no account.

Which Windows does it need?

Windows 10 or Windows 11, 64-bit. Any brand of laptop or desktop.

Does it need administrator rights?

Not to open. When an action needs them, such as repairing system files or resetting the network, Windows asks you first. You can also restart WinDiag as administrator from the bottom of its menu.

Can it break something?

The Checkup only reads. Every setting WinDiag changes can be set back from the same page, drivers get a restore point first, and each repair explains when to use it before you press Run.

Why does Windows say “Windows protected your PC”?

The installer isn’t code-signed yet, so SmartScreen doesn’t know it. Choose More info, then Run anyway. The whole code is public on GitHub.

Can I use it without installing it?

Yes. Each release also has a portable zip: extract it anywhere, even a USB drive, and open windiag.exe.

Where do the apps it installs come from?

From winget, Windows’ own app installer, straight from each maker or the Microsoft Store. WinDiag only offers a fixed list of 45 well-known apps.

Check your PC today.

Download WinDiag

Version 3.0.0 · Windows 10 and 11, 64-bit · Installer or portable zip