These use high-ratio compression (like .rar or .7z ) to shrink a full ISO. Once extracted, the file returns to its original size (e.g., a 10MB file extracting to 3.5GB ).
Any file claiming to be a fully functional Windows 7 ISO under 1GB is likely: windows 7 iso highly compressed
: Some "Lite" versions remove critical system components (like drivers or security features) to save space, making the system unstable . Recommended Way to Get a Windows 7 ISO These use high-ratio compression (like