Steam – tell Steam which monitor to open a game on

Yes, yes, yes! Due to the addition of the Fallout New Vegas issue, I was able to Google that and find this .dll, which proved to be helpful in solving the issue.

Just download the d3d9.dll linked here: Alternate D3D9 Fix for ATI.

Thanks a ton to the author of this .dll. I can confirm that it fixed the problem with both Fallout games and hope it can solve the same problem for other gamers too.

Now I can jump into the Fallout world again.

Ok, it does seem that going through the installscript.vdf and looking for everything under Run Process and putting that in the registry seems to get rid of the prompt. For example, for Assassin's Creed III I have this:

"Run Process"
{
    "DXSetup"
    {
        "process 1"     "%INSTALLDIR%\\Support\\DirectX\\DXSETUP.exe"
        "command 1"     "/silent"
        "NoCleanUp"     "1"
    }
    "VCRedist"
    {
        "HasRunKey"     "HKEY_LOCAL_MACHINE\\Software\\Valve\\Steam\\Apps\\208480"
        "process 1"     "%INSTALLDIR%\\Support\\VCRedist\\vcredist_x86.exe"
        "command 1"     "/q"
        "NoCleanUp"     "1"
    }
    "Punkbuster"
    {
        "process 1"     "%INSTALLDIR%\\Support\\Punkbuster\\pbsvc.exe"
        "command 1"     "/i --no-prompts --no-display --skip-tests --i-accept-the-pb-eula"
        "NoCleanUp"     "1"
    }
    "uplaylauncher"
    {
        "process 1"     "%INSTALLDIR%\\Support\\GameLauncher\\UplayInstaller.exe"
        "command 1"     "/S"
    }
    "kb971512_x86"
    {
        "Requirement_OS"
        {
            "OSType"        "Windows Vista"
            "Is64BitWindows"        "0"
        }
        "process 1"     "%WinDir%\\system32\\wusa.exe"
        "command 1"     "\"%INSTALLDIR%\\Support\\KB971512-x86.msu\" /quiet "
        "IgnoreExitCode"        "1"
    }
    "kb971512_x64"
    {
        "Requirement_OS"
        {
            "OSType"        "Windows Vista"
            "Is64BitWindows"        "1"
        }
        "process 1"     "%WinDir%\\system32\\wusa.exe"
        "command 1"     "\"%INSTALLDIR%\\Support\\KB971512-x64.msu\" /quiet /norestart "
    }
}

Adding each (DXSetup, VCRedist, ...) of those to the registry under Computer\HKLM\SOFTWARE\Wow6432Node\Valve\Steam\Apps\208480 as a DWORD with a value of 1 leaves me with only the UPlay prompt (which I think is a uplay problem and not a Steam problem). The whole process could probably be automated except that I don't see an easy way to find the number (208480) for the app. It's not contained in the install file itself, so I had to find it by searching for Assassin's Creed in the store.

If it has to be done manually like this, then it probably isn't worth the effort.