Add known scope issues (#3615)

Author: mattwojo

hub/package-manager/winget/install.md

@@ -42,7 +42,7 @@ The options allow you to customize the install experience to meet your needs.
 | **--moniker**   | Limits the search to the moniker listed for the application. |  
 | **-v, --version**  |  Enables you to specify an exact version to install. If not specified, latest will install the highest versioned application. |  
 | **-s, --source**   |  Restricts the search to the source name provided. Must be followed by the source name. |  
-| **--scope**   |  Allows you to specify if the installer should target user or machine scope. |  
+| **--scope**   |  Allows you to specify if the installer should target user or machine scope. See [known issues relating to package installation scope](./troubleshooting.md#scope-for-specific-user-vs-machine-wide).|  
 | **-a, --architecture**   |  Select the architecture to install. | 
 | **-e, --exact**   |   Uses the exact string in the query, including checking for case-sensitivity. It will not use the default behavior of a substring. |  
 | **-i, --interactive** |  Runs the installer in interactive mode. The default experience shows installer progress. |  

hub/package-manager/winget/settings.md

@@ -136,7 +136,7 @@ Any arguments passed on the command line will effectively override the matching
 
 #### scope
 
-The `scope` behavior affects the choice between installing a package for the current user or for the entire machine. The matching parameter is `--scope`, and uses the same values (`user` or `machine`).
+The `scope` behavior affects the choice between installing a package for the current user or for the entire machine. The matching parameter is `--scope`, and uses the same values (`user` or `machine`). See  [known issues relating to package installation scope](./troubleshooting.md#scope-for-specific-user-vs-machine-wide).
 
 ```json
 "installBehavior": {

hub/package-manager/winget/troubleshooting.md

@@ -33,3 +33,13 @@ If you need more comprehensive log files, that provide the complete communicatio
 ## Known issues
 
 A list of known issues with sources and behaviors is kept up to date in the [Windows Package Manager Client repository](https://www.github.com/microsoft/winget-cli).  If you encounter issues when using the winget tool, go [here](https://github.com/microsoft/winget-cli/tree/master/doc/troubleshooting) for troubleshooting.
+
+### Scope for specific user vs machine-wide
+
+Not all installers support installing in “user” scope vs. “machine” scope consistently.
+
+- [MSIX-based packages](/windows/msix/overview): Reliable WinGet behavior.
+- [MSI-based packages](/windows/win32/msi/installation-package) typically support reliable WinGet configurations, but in some cases, are nested inside an .exe-based installer so there may be more variability.
+- [EXE-based installers](https://stackoverflow.com/questions/3886455/whats-the-difference-between-an-exe-and-a-msi-installer) behavior around scope is not necessarily deterministic. In some cases the arguments to specify scope are not available, and in other cases the installer may make the determination based on whether the user is a member of the local administrators group. Packages installed in user scope may still require UAC (User Account Control) authorization from an administrator.
+
+See more details on [scope-related issues](https://github.com/microsoft/winget-cli/issues?q=is%3Aissue+is%3Aopen+label%3Aarea-scope) in the WinGet product repository on GitHub.