In the confirmation email, if you bought it online.

Directly on your computer, if it came pre-installed with Windows.

In the packaging, your Windows software originally came in.

To upgrade your operating system to Windows 10, just follow these steps: How to Upgrade your Operating System to Windows 10 Step 1: Locate your product key You can still download and run a trial version of Windows 10 without a product key but in order to activate it, you’ll need to enter the key that came with your original copy of Windows 7, 8, or 8.1. To learn a bit more about product keys see our guide here. Product keys are codes that Microsoft gives to each copy of Windows (or Microsoft Office) to help make sure it’s authentic and prevent counterfeiting. To take advantage of the free upgrade, however, you first need to have an authentic copy of Windows 7, 8, or 8.1 installed on your computer with a valid product key.

Describing it as a “universal app”, Windows 10 can be installed on multiple devices including PCs, tablets, and smartphones. Product keyWhen Microsoft released Windows 10 in July 2015, it allowed existing Windows 7, 8, and 8.1 users to upgrade for free.

Upgrade windows 7 to windows 8.1