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When you start up games you've bought for the first time it usually says "download directx" step 1/3" or something to that effect and then starts whatever game it is, also having the "Always keep game updated" tab marked in settings i'm assuming that the latest patch is automatic.
Now in some games you can clearly see what version you are playing(main menu, options etc.) but many doesn't seem to show it, also checking in the game steam folder usually doesn't show anything.
So for those cases how do I know if I have the latest version?
Sorcerer, king of dark intentions, pro skiller, sensual pleasures pirate, constant hankering for honey, sprinkly toes thrillseeker extraordinaire.
Find the game's main .exe file, right-click, Properties, then I think there's a Details tab (off the top of my head -- I'm not near a Windows machine right now). You can find the version number in there. Unfortunately it doesn't always match the way the developer calls the game's various versions.
-What is best in life?
-To crush your enemies, see them driven before you, and to hear the lamentation of the women.
Steam always updates you to the latest version they have. Where you check game version depends on the individual game tho - I'm not aware of any option in Steam that tells you what game version you're running for any particular game.
"How do I get rid of a Trojan Horse?" -Sailor_Kakashi
"Leave it outside the gates of Troy overnight." -Davel23
Why does DirectX install with every game?
So basically, it doesn't matter if you think you have the latest version of DirectX.... it's going to go through the motions of installing every time anyway.
Not sure if you mean "latest version of DirectX" or "latest version of the game I'm playing". Assuming the former DirectX isn't updated very frequently and it's not something you should ever have to worry about. Assuming the later Steam will always download patches for games you own as soon as they become available unless you have the "do not update" tab for them checked.