Windows 10 & Windows 11 (Pro / Home / Server)
- Open the Activation page
Start › Settings › System › Activation
Support Microsoft. - Click Change product key, paste the 25-character code you received by email, and press Next Support MicrosoftSupport Microsoft.
- Stay online for a few seconds while Windows contacts Microsoft’s servers; you’ll see “Windows is activated” when done Support Microsoft.
Tip: Re-entering the key also re-activates Windows after a major hardware swap like a new motherboard Support Microsoft.
Common errors
- 0xC004F050 – “Key invalid”
Make sure the edition matches the key (e.g., Pro vs Home) or try again after typing carefully Support MicrosoftSupport Microsoft. - Not activated after clean install
Open Settings › System › Activation and run the built-in troubleshooter Support Microsoft.
More fixes are listed in our FAQ page.
Office 2021 / 2024 (Retail or ISO keys)
- Install Office from the ISO or Microsoft Account portal.
- Launch Word (or any app) and you’ll be prompted to enter your product key; paste the code and sign in with your Microsoft account Support Microsoft.
- The Activation Wizard will confirm “Product Activated”—you’re set!
Redeeming first time? Go to office.com/setup, sign in, and enter the key to link it to your account Support Microsoft.
Microsoft 365 Subscriptions
- Visit office.com/setup and sign in (or create) your Microsoft account Support Microsoft.
- Enter the 25-character key, choose your country / language, and click Next.
- Download the apps and sign in on each device to finish activation.
Need help?
Most issues are solved in under 30 minutes.
• Check additional tips in our FAQ page.
• Email [email protected] or use the live-chat bubble on the Contact page.
• Detailed troubleshooting—including SLMGR command-line options—is covered in Microsoft’s knowledge base How-To Geek.
Why follow these steps?
- They mirror Microsoft’s official activation paths, ensuring the key is validated on Microsoft servers (Windows / Office) Support MicrosoftSupport Microsoft.
- Using the built-in Activation page avoids invalid-key errors and links the licence to your Microsoft account for future reinstalls How-To GeekHow-To Geek.
- Retail Office keys remain transferable—simply deactivate on the old PC and sign in on a new one
Follow the sections above in order, and you’ll have your new software running—fully activated—in just a few minutes.