I downloaded the steam version today in preparation to switch from win10 to steam.

After the steam version was done downloading, i started it to open the launcher in case it had any updates, there were none. So i clicked the big button to launch the game and received a "Cannot find 'd3dx9_43.dll'. Please, reinstall this application." error, and the game doesn't launch, even after i tried checking the box in the settings to not use directx9.

Normally in any other game this would tell me that i need to install or update directx9/10/11 etc. But the Windows 10 version still launches and plays without issue and I'm not entirely sure how to fix this. Not sure if this is a steam issue, a windows issue, a permissions issue, but it would sure be nice to fix it so i can finally switch to steam and not have both installed anymore.

Are you trying to launch the Steam version as an Administrator? That is required. Also, you might need to try re-verifying the files through Steam. You can also try re-installing the latest version of Directx. It sometimes gets corrupted without warning and needs re-installed.

Yes, I've gone through and made sure to run it as administrator. The steam "verify integrity of game files" option was grayed out, so i did it from the pso2 launcher and it didn't find an issue. I've also tried to update directX, but it tells me its up to date or newer is already installed. I did also explore the game directory and the the file exists in there, so its not missing from the game folder.

you're getting the dll error too? damn, that sucks.

im still looking for a solution myself...

I tried uninstalling the game and reinstalling it as well, just in case the file check messed up, and still didn't help. Kind of wanted to get the switch over to steam done this week because so i didn't have to deal with it later, im going to be installing a new SSD and reinstalling my OS in another week or two, and i didn't want to have to reinstall the windows version after that just to do this, but i might have to.

but isnt reinstalling the OS a bit too much?

I'm not reinstalling it because of this, its something i've had planned and finally got all the stuff together. I just wanted to take care of this issue before i did it because i'd rather not have to redownload from the windows store again just to transfer to steam after that.