Special Awareness When Trying Out Windows Copilot Runtime APIs in 1.7.0-experimental3 in C# Console App

[yeelam-gordon]

When trying to use the Windows Copilot Runtime APIs, such as Phi-Silica, in the 1.7.0-experimental3 release at a new Console app, you may encounter the following issues:

Execute at LanguageModel.CreateAsync() results in a System.Runtime.InteropServices.COMException '' (i.e. empty error message)
Execute at LanguageModel.IsAvailable() results in System.Runtime.InteropServices.COMException: 'Class not registered'

[yeelam-gordon]

Here are basically combined multiple docs information into this simple one.
The original docs are :

1. https://learn.microsoft.com/en-us/windows/apps/windows-app-sdk/preview-experimental-unpackaged-tutorial?tabs=csharp-dotnet-preview3
2. https://learn.microsoft.com/en-us/windows/apps/windows-app-sdk/deploy-unpackaged-apps#prerequisites
3. https://learn.microsoft.com/en-us/windows/apps/windows-app-sdk/use-windows-app-sdk-run-time

The following are based on ARM (for those machine with Arm-based Snapdragon Elite X+ chip), but it should be simple to change x64 if your NPU hardware in Intel.

In the csproj, here are 4 values need to be added, and we will talk one by one:

	<TargetFramework>net9.0-windows10.0.22621.0</TargetFramework>
	<WinPackageType>None</WinPackageType>
	<WindowsAppSdkBootstrapInitialize>true</WindowsAppSdkBootstrapInitialize>
       <Platforms>ARM64</Platforms>

1. For sure the prerequisites at https://learn.microsoft.com/en-us/windows/ai/apis/phi-silica#prerequisites

2. Target the right Framework and Windows Version.
   <TargetFramework>net9.0-windows10.0.22621.0</TargetFramework>
   It should be working for net8.0 as well, but haven't try.

3. Declare as unpackaged app explicitly
   <WinPackageType>None</WinPackageType>
   And given it is an unpackaged app, need to install the runtime explicitly.
   Install the ARM64 version of WinAppSDK 1.7 Experimental 3 from here https://learn.microsoft.com/en-us/windows/apps/windows-app-sdk/downloads#windows-app-sdk-17-experimental
   So far the download link is https://aka.ms/windowsappsdk/1.7/1.7.250127003-experimental3/windowsappruntimeinstall-arm64.exe

4. Do module initialization (the bootstrapper API)
   <WindowsAppSdkBootstrapInitialize>true</WindowsAppSdkBootstrapInitialize>
   All those API must be result in COMException given no bootstrap Initialization yet.

5. By default Console is using AnyCPU, but we need a specific Architecture value for WinAppSDK
   You need to ensure the Configuration in your solution define for ARM64, and as the result you will have
   <Platforms>ARM64</Platforms>

These steps should help avoid common pitfalls and ensure a smoother development experience! 🚀