Aktivierungshandbuch

Windows 10 & Windows 11 (Pro / Home / Server)

Open the Activation page
Start › Settings › System › Activation Microsoft-Support.
Klicken Produktschlüssel ändern, paste the 25-character code you received by email, and press Next Microsoft-Support Microsoft-Support.
Stay online for a few seconds while Windows contacts Microsoft’s servers; you’ll see “Windows is activated” when done Microsoft-Support.

Tip: Re-entering the key also re-activates Windows after a major hardware swap like a new motherboard Microsoft-Support.

Common errors

0xC004F050 – “Key invalid”
Make sure the edition matches the key (e.g., Pro vs Home) or try again after typing carefully Microsoft-Support Microsoft-Support.
Not activated after clean install
Open Settings › System › Activation and run the built-in troubleshooter Microsoft-Support.
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 Microsoft-Support.
The Activation Wizard will confirm “Product Activated”—you’re set!

Redeeming first time? Gehe zu office.com/setup, sign in, and enter the key to link it to your account Microsoft-Support.

Microsoft 365 Subscriptions

Visit office.com/setup and sign in (or create) your Microsoft account Microsoft-Support.
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) Microsoft-Support Microsoft-Support.
Using the built-in Activation page avoids invalid-key errors and links the licence to your Microsoft account for future reinstalls How-To Geek How-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.