Windows

Microsoft Windows (usually referred to as Windows) is an EXTREMELY common Operating System used on most computers. If you don't own a Mac and have no idea what Linux is, you are probably running Windows.
==Windows Versions==
Windows 1.x,
Windows 2.x,
Windows 3.x,
Windows NT 3.x,
Windows 95,
Windows NT 4.0,
Windows 98,
Windows 98 SE,
Windows 2000,
Windows ME,
Windows Whistler,
Windows XP,
Windows Server 2003,
Windows Longhorn,
Windows Vista,
Windows Server 2008,
Windows 7,
Windows Server 2008 R2 &
Windows 8
==Touhou==
Touhou on Windows was not available until the release of Embodiment of Scarlet Devil. Before hand, there were the PC-9801 Touhous.
Versions of Touhou for Windows:
*6: Embodiment of Scarlet Devil
*7: Perfect Cherry Blossom
**7.5: Immaterial and Missing Power
*8: Imperishable Night
*9: Phantasmagoria of Flower View
**9.5: Shoot the Bullet
*10: Mountain of Faith
**10.5: Scarlet Weather Rhapsody
*11: Subterranean Animism
*12: Undefined Fantastic Object
**12.3: Hisotensoku
**12.5: Double Spoiler
**12.8: Great Fairy Wars
*13: Ten Desires
**13.5: Hopeless Masquerade