[header] How to install directx [title] Determine the version of directx your system is currently using. [step] Operating systems released prior to windows vista are not compatible with certain components of the directx application programming interface (api). Windows xp and earlier versions of windows will not run correctly with the latest version of directx, as it is not not backwards compatible. 
Follow the steps to discover which version of directx is currently installed on your computer. [substeps] Open the start menu and select " run.