Can Win10 Technology Preview be upgraded to the official version if it needs to be activated?

After the launch of Windows 10 Technical Preview, many users have downloaded the latest system of installation experience. However, there are also users who have concerns. Now install the Win10 technology preview directly on Win8.1. Do you know if the official version can be overwritten directly after installation? Do you need to activate?

Based on past experience, The preview version can be upgraded directly to the official version. After upgrading the official version, the activation key of Windows 10 is required.

Explain the secret key mechanism of the Windows system. Each version of the secret key can only activate this version. The activation key of Windows 8.1 is different from the KEY of Windows 10, and it cannot be activated by Windows 8.1. To activate Windows 10. But in the future, Windows 8.1 will need to pay for the upgrade of Windows 10, and there is no relevant news for the time being. Even if you don't need to pay extra in the future, you need to install Windows 8.1 first and upgrade Windows 10.

Referring to the experience of Win8, after the technical preview, Windows 10 will also have a consumer preview or other test version. The official version of the launch may be in the second half of next year, when we can upgrade to the official version of Win10.