Looking at the Microsoft page for the August DirectX redistibutable it gives the following list of supported OS's System Requirements * Supported Operating Systems: Windows 7; Windows Essential Business Server; Windows Fundamentals for Legacy PCs; Windows Home Server; Windows Server 2003; Windows Server 2003 Service Pack 1; Windows Server 2003 Service Pack 2; Windows Server 2003 Service Pack 2 x64 Edition; Windows Server 2003 x64 editions; Windows Server 2003, Datacenter Edition (32-bit x86); Windows Server 2003, Datacenter x64 Edition; Windows Server 2003, Enterprise Edition (32-bit x86); Windows Server 2003, Enterprise x64 Edition; Windows Server 2003, Standard Edition (32-bit x86); Windows Server 2003, Standard x64 Edition; Windows Server 2003, Web Edition; Windows Server 2008; Windows Server 2008 Datacenter; Windows Server 2008 Datacenter without Hyper-V; Windows Server 2008 Enterprise; Windows Server 2008 Enterprise without Hyper-V; Windows Server 2008 Service Pack 2; Windows Server 2008 Standard; Windows Server 2008 Standard without Hyper-V; Windows Small Business Server 2003 ; Windows Small Business Server 2008 Premium; Windows Small Business Server 2008 Standard ; Windows Vista; Windows Vista 64-bit Editions Service Pack 1; Windows Vista Business; Windows Vista Business 64-bit edition; Windows Vista Enterprise; Windows Vista Enterprise 64-bit edition; Windows Vista Home Basic; Windows Vista Home Basic 64-bit edition; Windows Vista Home Premium; Windows Vista Home Premium 64-bit edition; Windows Vista Service Pack 1; Windows Vista Service Pack 2; Windows Vista Starter; Windows Vista Ultimate; Windows Vista Ultimate 64-bit edition; Windows Web Server 2008; Windows XP; Windows XP 64-bit; Windows XP Embedded; Windows XP Embedded Service Pack 1; Windows XP Embedded Service Pack 2 ; Windows XP Home Edition ; Windows XP Media Center Edition; Windows XP Media Center Edition 2005 Update Rollup 2; Windows XP Professional Edition ; Windows XP Professional x64 Edition ; Windows XP Service Pack 1; Windows XP Service Pack 2; Windows XP Service Pack 3; Windows XP Starter Edition; Windows XP Tablet PC Edition So it appears the original list posted here is the same as MajorGeeks which is incorrect.