Windows XP Professional on a dual 200 MHz Pentium Pro system from January 1997.
(I believe this originally came with Windows NT Workstation 4.0)
Specs:-
Processor: Dual Intel Pentium Pro 200 MHz, 66 MHz Bus, 256kb L2 Cache
Chipset: Intel 440FX
Motherboard: Intel PR440FX
RAM: 128MB 60ns EDO ECC
Hard Drive: Quantum Fireball ST 6.4 GB
Video Card: Number Nine Imagine 128 Series 2 8MB
Sound Card: Integrated Crystal WDM Audio
Ethernet: Integrated Intel EtherExpress PRO 82557 10/100 LAN Controller
Power Supply: 230W Unknown Brand
Case: In-Win A500
CD-ROM: Mitsumi FX120T
DVD-ROM: Some Random Hitachi
Floppy: No Idea
