In this video, you will see how you can download ISO images of Windows 10 Insider Preview builds 15042|15025 (Slow Ring)
1. Visit this page: https://goo.gl/vga6x8 (Official Microsoft Page)
2. Select the edition of Windows 10 Insider Preview Build
3. Select the Product language
4. Select 32 bit or 64-bit edition of the product
5. And download will start instantly