Some hard disk space controllers always try their best to delete software they think they don't need, but some software is better to keep, such as directx. If you don't have directx on your computer, you won't be able to play many games.
directx is a widely used API developed by Microsoft, which is widely used in video game development for multiple platforms under Microsoft. DirectX enhances 3D graphics and sound effects, and provides designers with a common hardware driver standard, so that game developers do not have to write different drivers for each brand of hardware, and it also reduces the complexity of installing and setting up hardware for users.
The most familiar one in DirectX is Direct3D, which is the rendering part. In addition, there are Input, Sound, Show, Compute, etc. DirectX defines a specification for the equipment required by a game, the equipment manufacturer is responsible for implementing the specification, and then DirectX wraps a thin layer of API on top of this specification and then gives it to you. The latter is what you see as DirectX functions.
DirectX 9 is the latest version of DirectX technology (now DirectX 10.0) at the end of 2002, providing higher performance for games and other multimedia software programs that use DirectX. The role of Directx9 is to improve the performance of the graphics card.
Reference: http://www.285868.com/jiaocheng/jpc/show-11073.html