Hi,
I think DirectX is meant to be backwards compatible,you used to be able to update it from say 7-8-9 but once you update i don`t think you can go back,the only way to go back would be to reinstall your O.S. I think nowadays it is O.S. and your graphic card dependent,win7 can only update to DirectX 11 even if your gpu supports higher. I run win7 and I still play games that run DirectX 8,so you need not worry about looking for different direct x versions. I`ve been loading alot of old game onto my pc lately and if they offer to load older versions of directx i just skip over that part,some games automatically say updating directx even when I`m running a newer version then the one installed on my pc but all seems to work as intended.