You're looking for a lightweight version of Windows 8 64-bit. Here are a few options:
The "Super Lite" versions became a cult favorite because they did the impossible: they made a 10-year-old laptop feel faster than a modern one. Upon boot-up, instead of using 1.5GB of RAM, these versions would sit at a mere 400MB to 600MB. It was the OS "distilled"—no tracking, no animations, just raw speed. The Dark Side windows 8 super lite 64 bits full
Performance Tweaks: Systems are often pre-optimized for faster boot times and more responsive window management. Why Choose the 64-Bit Version? You're looking for a lightweight version of Windows 8 64-bit
Third-Party Options: