First, backup your personal files to an external drive and save any licence keys you will need to reinstall applications. Then, do the free upgrade to Windows 10: [URL]  After upgrading, check to see if Windows 10 is activated in Settings | Activation. If it is, then you can perform a clean install of Windows 10 and it should activate automatically. The clean install will result in a better system than just staying with the in-place upgrade. Here are my detailed steps to perform a clean install of Windows 10. Here's another description of the install process, from a Microsoft MVP. P.S. When Dell says that Windows 10 is not supported on an older laptop, it just means that they won't provide warranty support for that laptop with Windows 10, and may not issue drivers for it. But, since your laptop is long past warranty anyway, it's irrelevant. I have installed Windows 10 on laptops older than yours, and it works well.
Hello, I have an old Dell XPS13 laptop (Build 9333) that has run flawlessly for many  years. I have previously tired to upgrade this to Windows 10 but, told it was not supported. This was quite a shock to me havingspent so much money on the laptop but, I've finally hit the wall with the dreaded "You need to upgrade as no longer supported" type messages popping up. I've had another look and it seems that Windows 10 is now supported: [URL] The laptop itself is well out of suppport so I'd really appreciate a steer on how I can get this machine onto Windows 10? Thank you. Stewart.
Dell XPS 13 9333 - Windows 10 Upgrade