Windows 8.1 Pro Super Lite Extreme 32 64-bit
I tested a stock Windows 11 vs. Windows 8.1 Pro Super Lite Extreme on a Dell Latitude E6420 (Intel i5-2520M, 4GB DDR3, 120GB SSD).
Always include a disclaimer:
Anecdotal benchmarks suggest these "Extreme" builds can reduce the installation footprint from approximately 15-20 GB to under 4 GB. RAM usage on idle has been observed to drop from ~1 GB to ~400 MB, making the OS viable for systems with only 2 GB of RAM. Windows 8.1 Pro Super Lite Extreme 32 64-bit