Download Windows 10

[Lloyd_mcse]

If you need to install or reinstall Windows 10, you can use the tools on this page to create your own installation media using either a USB flash drive or a DVD.

Before you begin

• Make sure you have:
  
  • An internet connection (internet service provider fees may apply).
  • Sufficient data storage available on a computer, USB or external drive for the download.
  • A blank USB or DVD (and DVD burner) with at least 4 GB of space if you want to create media. We recommend using a blank USB or blank DVD, because any content on it will be deleted.
  
  
• Read the System Requirements.
• If you will be installing the operating system for the first time, you will need your Windows product key (xxxxx-xxxxx-xxxxx-xxxxx-xxxxx). For more information about product keys and when they are required, visit the FAQ page.
• For Enterprise editions please visit the Volume Licensing Service Center.

Use the media creation tool to download Windows. This tool provides the best download experience for customers running Windows 7, 8.1 and 10. To learn how to use the tool, go to the Installing Windows 10 using the media creation tool page. Tool includes:

• File formats optimized for download speed.
• Built in media creation options for USBs and DVDs.
• Optional conversion to ISO file format.

Read more at Microsoft

[Lloyd_mcse]

A couple of my own points,

• Suspend BitLocker before you start the installation
• Disable Hyper-V before you start the installation

Other than that, it's been plain sailing on the two upgrades I have done so far.
Good luck!