How to Fix Windows 10 Activation Error 0xc0020036 Easily

Uh-oh! Running into the Windows 10 Activation Error 0xc0020036? Don’t worry, you’re not alone. Thousands of users face this annoying message. Luckily, it’s not as scary as it looks. Let’s walk through some easy, bite-sized steps to fix it. You don’t need to be a tech wizard — just follow along!

What Does Error 0xc0020036 Mean?

This error usually pops up when your Windows 10 key isn’t working right. Maybe it’s:

Missing
Invalid
Blocked by Microsoft
Linked to different hardware

It’s like trying to enter a party with the wrong invite. Windows sees the key, says “nope!” and locks you out of full access. But don’t panic — we’ve got fixes!

Step 1: Restart Your PC

The age-old trick. It sounds too simple, right? But sometimes a fresh boot solves a surprising number of problems.

Click the Start menu
Select Power
Hit Restart

Once your PC reboots, check if the activation error is gone.

Step 2: Run the Activation Troubleshooter

Windows has its own magic wand—the Activation Troubleshooter.

Click the Start menu and tap Settings
Go to Update & Security > Activation
If you see “Windows is not activated,” click Troubleshoot

Windows will try to figure out the issue and may fix it all by itself. Like your little personal tech assistant!

Step 3: Re-Enter Your Product Key

Maybe the key got corrupted or lost. Re-typing it can help.

Go to Settings > Update & Security > Activation
Click Change product key
Enter your 25-character key

If you don’t have it, check your email, packaging, or Microsoft account.

Step 4: Use the Command Line (Not as Scary as It Sounds!)

This fix needs the Command Prompt. Follow closely:

Right-click the Start button
Select Command Prompt (Admin) or Windows PowerShell (Admin)
Type in: slmgr /ipk YOUR-PRODUCT-KEY and hit Enter
Then type: slmgr /ato to activate

Replace “YOUR-PRODUCT-KEY” with your real key, of course!

Step 5: Check If Hardware Changed

If you recently upgraded your motherboard or hard drive, Windows might think it’s a new computer.

Here’s what to do:

Open Settings > Update & Security > Activation
Click Troubleshoot
Select I changed hardware on this device recently
Sign in to your Microsoft account

Windows will try to match your key to the new hardware.

Step 6: Call in the Big Guns

Still stuck? Time to call Microsoft support. They’re not scary, promise.

Press Windows + R, type slui 4, and press Enter
Select your country or region
You’ll get a toll-free number to call

Explain your issue. They might give you a new activation code.

Bonus Tip: Check Windows Version

Make sure your key matches your version of Windows.

A Windows 10 Home key won’t work on Windows 10 Pro
To check: Settings > System > About

If the versions don’t match, reinstall Windows or get the right license.

Wrapping It Up

Activation Error 0xc0020036 can be annoying, but it’s usually easy to fix.

Just take it one step at a time:

Try restarting
Use the troubleshooter
Re-enter your key
Use command line tools if needed
Check for hardware changes

If all else fails — Microsoft support has your back.

Now go conquer that error like a pro! Your Windows will be activated and stress-free in no time.