You're looking for information on a lightweight version of Windows 7, specifically "Windows 7 Super Nano Lite X86". Here's what I found:
Use Offline: For maximum safety, use this OS for offline tasks like retro gaming, running old diagnostic software, or as a dedicated writing station. windows 7 super nano lite x86
Activation: Some versions claim to have activation components removed or do not require a key, though it is always recommended to use a genuine product key if possible. You're looking for information on a lightweight version
If you are going to use this build:
Developer: Originally created by blzos and modified by AThePetrov. ISO Size: Approximately 321 MB. running old diagnostic software