Windows 10 on my i7 4790k gaming PC with 16GB DDR3 1866, MSI Z87 ATX Motherboard, Antec 1100 Case with 6 case fans, 250GB Samsung SSD, 3TB Western Digital Green HDD, EVGA Geforce GTX 970, 850W Silverstone PSU . I have one running 7 Home Premium x64: Dell XPS 400 Pentium D 945 3.4GHz and 4 GB DDR2 667 and a 2GB AMD Radeon R7 250 graphics card (Windows 7 saved this PC) My final PC is running the unofficial SP4 of XP Professional: Dell Dimension 8300 (dating back to April of 2004!) Pentium 4 3.0 GHz 800 FSB Northwood Socket 478 PC Intel 875x chipset 3GB DDR 400 512MB ATI Radeon HD 3650 AGP 8x GPU 250GB hard drive