title: .Net Core 2.0 Process.Start throws "The specified executable is not a valid application for this OS platform"
body: <p>I need to let a .reg file and a .msi file execute automatically using whatever executables these two file types associated with on user's Windows.</p>
  
  <p><a href="https://docs.microsoft.com/en-us/dotnet/api/system.diagnostics.process.start?view=netcore-2.0#System_Diagnostics_Process_Start_System_String_" rel="noreferrer">.NET Core 2.0 Process.Start(string fileName) docs</a> says:
  "the file name does not need to represent an executable file. It can be of any file type for which the extension has been associated with an application installed on the system."</p>
  
  <p>However</p>
  
  <pre><code>using(var proc = Process.Start(@"C:\Users\user2\Desktop\XXXX.reg")) { } //.msi also
  </code></pre>
  
  <p>gives me</p>
  
  <pre><code>System.ComponentModel.Win32Exception (0x80004005): The specified executable is not a valid application for this OS platform.
     at System.Diagnostics.Process.StartWithCreateProcess(ProcessStartInfo startInfo)
     at System.Diagnostics.Process.Start()
     at System.Diagnostics.Process.Start(ProcessStartInfo startInfo)
     at System.Diagnostics.Process.Start(String fileName)
  </code></pre>
  
  <p>with ErrorCode and HResult -2147467259, and NativeErrorCode 193.</p>
  
  <p>The same code did work in .Net Framework 3.5 or 4 console app.</p>
  
  <p>I can't specify exact exe file paths as the method's parameter since users' environments are variant (including Windows versions) and out of my control. That's also why I need to port the program to .Net Core, trying to make it work as <a href="https://docs.microsoft.com/en-us/dotnet/core/deploying/deploy-with-vs#simpleSelf" rel="noreferrer">SCD</a> console app so that installation of specific .Net Framework or .NET Core version is not required.</p>
  
  <p>The exception is thrown both in Visual Studio debugging run and when published as win-x86 SCD. My PC is Win7 64bit and I'm sure .reg and .msi are associated with regular programs as usual Windows PC does.</p>
  
  <p>Is there solution for this? Any help is appreciated.</p>