Microsoft has released the first testing build of Windows 10 Technical Preview for Phones available for free download to public. Follow below steps to download Windows 10 Technical Preview Build for Phones.
STEP 1: Check Supported Phone Models List
This first preview build of Windows 10 for phones can be installed in following phones only,support for more phones will be added in future builds.
- Lumia 630
- Lumia 635
- Lumia 636
- Lumia 638
- Lumia 730
- Lumia 830
STEP 2: Join Windows Insider Program
you can download and install Windows 10 Technical Preview build by first joining Windows Insider program: Join Windows Insider Program
STEP 3: Register Phone to Receive Windows 10 Build as OTA Update
download and install Windows Insider app in your phone using any of following links: Download Windows Insider App
Alternatively, you can also install the app by searching for Windows Insider app using Store in your Windows phone.
STEP 4: Download Windows 10 Technical Preview Build for Phones
After installing Windows Insider app, open the app and sign in using same Microsoft account. Follow the instructions to download and install Windows 10 Technical Preview.