The Windows Insider Program is now live, so the Windows 10 Technical Preview and it’s ISO. To download the Windows 10 ISO, you need to visit Windows Insider Program page and need to click ‘Join now’ button, which then asks to sign in to your Microsoft account, after sign in, visit this page, scroll down a bit and note down the Product key and click on the download button for English 64-bit (x64) or English 32bit (x86).
Tips:
Download Windows 10 Technical Preview ISO 32-bit |3.16 GB
Download Windows 10 Technical Preview ISO 64-bit | 4.10 GB