{"id":412,"date":"2026-11-10T09:00:57","date_gmt":"2026-11-10T17:00:57","guid":{"rendered":"https:\/\/devblogs.microsoft.com\/insidemsix\/?p=412"},"modified":"2026-11-05T22:59:36","modified_gmt":"2026-11-06T06:59:36","slug":"activation-via-appusermodelid","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/insidemsix\/activation-via-appusermodelid\/","title":{"rendered":"Activation via AppUserModelId"},"content":{"rendered":"

An application can be directly\nactivated<\/a> by calling\nIApplicationActivationManager::ActivateApplication()<\/a>\nwith its Application User Model ID<\/a>,\nalso known as AppUserModelId or AUMID.<\/p>\n

For example, let’s use a package with this AppxManifest.xml<\/code> fragment:<\/p>\n

<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<Package ...>\n  <Identity Name=\"Contoso.PointOfSale\"\n            Publisher=\"CN=Contoso LLC, O=Contoso LLC, L=Paris, C=France\"\n            Version=\"1.2.3.4\"\n            ProcessorArchitecture=\"x64\" \/>\n  ...\n  <Applications>\n    <Application Id=\"CardReader\" Executable=\"PointOfSale.exe\" ...>\n...\n<\/Package>\n<\/code><\/pre>\n
This package’s full name is Contoso.PointOfSale_1.2.3.4_x64__eh4htm4n7tdre<\/code>.<\/p>\n
The eh4htm4n7tdre<\/code> suffix is the publisher ID derived from the package’s publisher.<\/p>\n
Its package family name is therefore Contoso.PointOfSale_eh4htm4n7tdre<\/code>.<\/p>\n
The <Application><\/code>‘s Id<\/code> attribute is the application’s\nPackage Relative Application Id<\/a>,\nalso known as PRAID.<\/p>\n
An AUMID is a combination of the application’s package family name and PRAID:<\/p>\n
AUMID = <PackageFamilyName> \"!\" <PRAID>\n<\/code><\/pre>\n
Thus the card reader’s AUMID is Contoso.PointOfSale_eh4htm4n7tdre!CardReader<\/code>. We can now activate\nthe application via its AUMID.<\/p>\n
Building StartApp.exe<\/h2>\n
Let’s create StartApp.exe<\/code> demonstrating activation via AppUserModelId in C, C++, and C#.<\/p>\n
StartApp.c<\/h2>\n
Windows doesn’t provide a convenient way to activate an application given an AUMID, so let’s make one.<\/p>\n
StartApp.exe<\/code> activates an app by AUMID. Here’s a minimal low-level implementation:<\/p>\n
#define COBJMACROS\n#include <windows.h>\n#include <shobjidl.h>\n\nHRESULT Run(PCWSTR appUserModelId, PCWSTR parameters, DWORD* processId)\n{\n    IApplicationActivationManager *aam = NULL;\n    HRESULT hr = S_OK;\n\n    if (appUserModelId == NULL || *appUserModelId == L'\\0' || processId == NULL)\n    {\n        return E_INVALIDARG;\n    }\n\n    hr = CoCreateInstance(&CLSID_ApplicationActivationManager, NULL,\n        CLSCTX_INPROC_SERVER, &IID_IApplicationActivationManager, (void**)&aam);\n    if (FAILED(hr))\n    {\n        return hr;\n    }\n\n    hr = IApplicationActivationManager_ActivateApplication(aam,\n        appUserModelId, parameters != NULL ? parameters : L\"\", AO_NONE, processId);\n\n    IApplicationActivationManager_Release(aam);\n\n    return hr;\n}\n\nint wmain(int argc, wchar_t* argv[])\n{\n    HRESULT hr = S_OK;\n    DWORD processId = 0;\n\n    if (argc < 2)\n    {\n        wprintf(L\"Usage: StartApp.exe <aumid>\\n\");\n        return ERROR_INVALID_PARAMETER;\n    }\n\n    hr = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);\n    if (FAILED(hr))\n    {\n        return hr;\n    }\n\n    hr = Run(argv[1], NULL, &processId);\n    if (SUCCEEDED(hr))\n    {\n        wprintf(L\"StartApp activated %ls: PID %u\\n\", argv[1], processId);\n    }\n    else\n    {\n        fwprintf(stderr, L\"StartApp failed to activate %ls: 0x%08lX\\n\",\n            argv[1], (unsigned long)hr);\n    }\n\n    CoUninitialize();\n\n    return (int)hr;\n}\n<\/code><\/pre>\n
Pretty basic but it gets the job done. This creates the ApplicationActivationManager<\/code> (AAM) instance\nand calls its ActivateApplication()<\/code> method with the AUMID, with basic error handling throughout.<\/p>\n
But we can do better.<\/p>\n
StartApp.cpp<\/h2>\n
Next, let’s add support for parameters.<\/p>\n
We’ll also switch to Modern C++ and\nWindows Implementation Library<\/a> (WIL) for ease of use and improved error handling.<\/p>\n
#include <windows.h>\n#include <shobjidl.h>\n\n#include <string>\n\n#include <wil\/com.h>\n#include <wil\/resource.h>\n#include <wil\/result.h>\n\nDWORD Run(const std::wstring& appUserModelId, const std::wstring& parameters)\n{\n    THROW_HR_IF(E_INVALIDARG, appUserModelId.empty());\n\n    auto aam{ wil::CoCreateInstance<IApplicationActivationManager>(CLSID_ApplicationActivationManager) };\n\n    DWORD processId{};\n    THROW_IF_FAILED(aam->ActivateApplication(\n        appUserModelId.c_str(), parameters.c_str(), AO_NONE, &processId));\n\n    return processId;\n}\n\nint wmain(int argc, wchar_t* argv[])\n{\n    if (argc < 2)\n    {\n        std::fwprintf(stderr, L\"Usage: StartApp.exe <aumid> [parameters...]\\n\");\n        return ERROR_INVALID_PARAMETER;\n    }\n\n    const std::wstring appUserModelId{ argv[1] };\n\n    \/\/ Handling backslashes, quotes, spaces and other complexities in argv\n    \/\/ is left as an exercise for the reader :-)\n    std::wstring parameters;\n    for (int index = 2; index < argc; ++index)\n    {\n        if (index > 2)\n        {\n            parameters += L' ';\n        }\n        parameters += argv[index];\n    }\n\n    try\n    {\n        const auto com{ wil::CoInitializeEx(COINIT_APARTMENTTHREADED) };\n\n        const auto processId{ Run(appUserModelId, parameters) };\n        wprintf(L\"StartApp activated %ls with \\\"%ls\\\": PID %u\\n\",\n            appUserModelId.c_str(), parameters.c_str(), processId);\n    }\n    catch (const wil::ResultException& ex)\n    {\n        std::fwprintf(stderr, L\"StartApp failed to activate %ls: 0x%08lX\\n\",\n            appUserModelId.c_str(), static_cast<unsigned long>(ex.GetErrorCode()));\n        return static_cast<int>(ex.GetErrorCode());\n    }\n\n    return 0;\n}\n<\/code><\/pre>\n
StartApp.exe<\/code> is both simpler and more capable thanks to C++ and WIL. Modern C++ eliminates much of\nthe manual resource management, while WIL provides concise COM helpers and consistent\nexception-based error handling.<\/p>\n
StartApp.cs<\/h2>\n
For bonus points, here’ a C# implementation.<\/p>\n
using System;\nusing System.Runtime.InteropServices;\n\ninternal static class Program\n{\n    private const uint AO_NONE = 0;\n\n    [ComImport]\n    [Guid(\"45BA127D-10A8-46EA-8AB7-56EA9078943C\")]\n    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]\n    private interface IApplicationActivationManager\n    {\n        int ActivateApplication(\n            [MarshalAs(UnmanagedType.LPWStr)] string appUserModelId,\n            [MarshalAs(UnmanagedType.LPWStr)] string arguments,\n            uint options,\n            out uint processId);\n\n        int ActivateForFile(\n            IntPtr itemArray,\n            [MarshalAs(UnmanagedType.LPWStr)] string verb,\n            out uint processId);\n\n        int ActivateForProtocol(\n            IntPtr itemArray,\n            out uint processId);\n    }\n\n    [ComImport]\n    [Guid(\"2E941141-7F97-4756-BA1D-9DECDE894A3D\")]\n    private sealed class ApplicationActivationManager\n    {\n    }\n\n    private static uint Run(string appUserModelId, string parameters)\n    {\n        ArgumentException.ThrowIfNullOrWhiteSpace(appUserModelId);\n\n        var aam = (IApplicationActivationManager)new ApplicationActivationManager();\n\n        var hr = aam.ActivateApplication(\n            appUserModelId, parameters, AO_NONE, out var processId);\n\n        Marshal.ThrowExceptionForHR(hr);\n\n        return processId;\n    }\n\n    public static int Main(string[] args)\n    {\n        if (args.Length < 1)\n        {\n            Console.Error.WriteLine(\n                \"Usage: StartApp.exe <aumid> [parameters...]\");\n            return 2;\n        }\n\n        var appUserModelId = args[0];\n\n        \/\/ Handling backslashes, quotes, spaces and other complexities in argv\n        \/\/ is left as an exercise for the reader :-)\n        var parameters = string.Join(\" \", args[1..]);\n\n        try\n        {\n            var processId = Run(appUserModelId, parameters);\n\n            Console.WriteLine(\n                $\"StartApp activated {appUserModelId} with \\\"{parameters}\\\": PID {processId}\");\n\n            return 0;\n        }\n        catch (Exception ex)\n        {\n            Console.Error.WriteLine(\n                $\"StartApp failed to activate {appUserModelId}: {ex.HResult:X8}\");\n\n            return ex.HResult;\n        }\n    }\n}\n<\/code><\/pre>\n
Activation via AppUserModelId from the Command Line<\/h2>\n
Activation by AUMID is fine, but not always convenient. Some tools only know how to run programs via\na command line. Windows doesn’t include a utility like StartApp.exe<\/code> to facilitate activation by\nAUMID.<\/p>\n
You can programmatically define a shortcut on the StartMenu to launch a packaged app by AUMID but\nFile Explorer’s right-click context menu’s New > Shortcut<\/code> won’t accept an AUMID directly.<\/p>\n
Is there another option?<\/p>\n
Of course.<\/p>\n
We’ll explore several options in the next blog post…<\/p>\n","protected":false},"excerpt":{"rendered":"
An application can be directly activated by calling IApplicationActivationManager::ActivateApplication() with its Application User Model ID, also known as AppUserModelId or AUMID. For example, let’s use a package with this AppxManifest.xml fragment: <?xml version=”1.0″ encoding=”utf-8″?> <Package …> <Identity Name=”Contoso.PointOfSale” Publisher=”CN=Contoso LLC, O=Contoso LLC, L=Paris, C=France” Version=”1.2.3.4″ ProcessorArchitecture=”x64″ \/> … <Applications> <Application Id=”CardReader” Executable=”PointOfSale.exe” …> … <\/Package> […]<\/p>\n","protected":false},"author":911,"featured_media":101,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[28,17,9,2,35],"class_list":["post-412","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-msix","tag-activation","tag-application","tag-code","tag-msix","tag-tools"],"acf":[],"blog_post_summary":"
An application can be directly activated by calling IApplicationActivationManager::ActivateApplication() with its Application User Model ID, also known as AppUserModelId or AUMID. For example, let’s use a package with this AppxManifest.xml fragment: <?xml version=”1.0″ encoding=”utf-8″?> <Package …> <Identity Name=”Contoso.PointOfSale” Publisher=”CN=Contoso LLC, O=Contoso LLC, L=Paris, C=France” Version=”1.2.3.4″ ProcessorArchitecture=”x64″ \/> … <Applications> <Application Id=”CardReader” Executable=”PointOfSale.exe” …> … <\/Package> […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/posts\/412","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/users\/911"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/comments?post=412"}],"version-history":[{"count":1,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/posts\/412\/revisions"}],"predecessor-version":[{"id":413,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/posts\/412\/revisions\/413"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/media\/101"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/media?parent=412"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/categories?post=412"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/insidemsix\/wp-json\/wp\/v2\/tags?post=412"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}