How to activate Windows with a product key
Short answer
In Windows 11, open Settings > System > Activation, select Change next to "Change product key", type the 25-character key and select Next. In Windows 10 the same option is under Settings > Update & Security > Activation. Your PC needs an internet connection to activate.
Before you start
- Have the 25-character product key ready. It is written as five groups of five letters and numbers: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX.
- Check which edition you are running: open Settings > System > About and look under "Windows specifications". A key activates the edition it was made for, such as Home or Pro.
- Connect to the internet. Activation checks the key with Microsoft.
Activate Windows 11
- Select Start, then Settings.
- Go to System, then Activation.
- Next to "Change product key", select Change.
- Enter the 25-character key and select Next.
- Follow the prompts. When it finishes, the Activation page says Windows is activated.
Activate Windows 10
- Select Start, then Settings.
- Go to Update & Security, then Activation.
- Select "Change product key".
- Enter the key, select Next, then Activate.
Windows 10 reached the end of support on October 14, 2025, and no longer receives regular security updates. If your PC meets the requirements, Windows 11 is the safer choice for a new install.
If activation fails
- Edition mismatch. A Pro key entered on a PC running Home starts an upgrade to Pro, and a Home key will not activate Pro. Make sure the key matches the edition you want.
- Typing errors. Some characters are easy to misread. Copy and paste the key from your email if you can.
- No connection, or the server is busy. Wait a few minutes and try again from the Activation page.
- After a hardware change. Replacing the motherboard can make Windows ask for activation again. Run the Activation troubleshooter from the Activation page. Linking your licence to a Microsoft account beforehand makes this easier.
Bought your key at LicenceBase and it will not activate? Reply to your order email with the error message. We check the key and replace it under the refund policy.
Where to get a Windows key in Canada
Microsoft sells Windows licences in its own store and through retailers. The Windows Serial Key at LicenceBase costs $7.45 CAD, paid once and emailed with step-by-step activation help. If you need a specific edition, such as Home or Pro, email us before you buy and we confirm which key you will receive.
Frequently asked questions
Can I use one product key on two PCs?
No. Each Windows licence covers one device at a time, and the keys LicenceBase sells are for one PC.
Do I need to reinstall Windows to activate it?
No, as long as the key matches the edition that is installed. You enter it on the Activation page of the running system.
How do I check that Windows is activated?
Open Settings, then System, then Activation (Update & Security, then Activation, in Windows 10). The page shows the activation state.
LicenceBase sells some of the products mentioned here. LicenceBase prices are read live from the store; brand prices show the date they were checked on the brand's own site.
