If this does not occur, you may need to launch them manually. The Steam platform should run any required installers when the game is initially launched. This could include DirectX, PhysX, C++ components, or Windows Updates. If a game launch is cancelled or interrupted, it is possible that your computer will be missing programs or services that the game needs to run. Disable any unnecessary programs and try to launch the game again. Programs running in the background can, in some cases, cause issues when launching new games. These are local configuration files and should not be altered in this process. Please Note: One or more files may fail to verify, in most cases this is normal.
Once you have launched it, allow it to identify, download, and install any required updates and try launching the game again. If you are having trouble locating it, use the Search programs and files function from the Start menu to find it. Please note that its location may differ based on your version of Windows. You can find it by navigating to your Start menu, selecting All Programs and then selecting Windows Update. To ensure your version of Windows has all the latest updates, you should run Windows Update. Ensure your version of Windows is Updated To run Steam as an Administrator, find the Steam executable instead (here by default: C:\Program Files (x86)\Steam) and follow the same process as above.
Once complete, restart Steam and try launching the game again.
You can download and install latest drivers (based on manufacturer) here: If your PC (Steam) copy of The Elder Scrolls V: Skyrim Special Edition is not launching after pressing Play, is stuck at the "Preparing to Launch" text box, or is running in the background but not actually launching, you can try the following troubleshooting steps: Update Your Graphics Card Drivers