Question

How do I list all programs installed on my computer? I’ve tried using the MsiEnumProducts and MsiGetProductInfo functions, but they do not return a full list of installed applications like I see in “Add/Remove Programs”.

Answer 1

Enumerate the registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall

bool EnumInstalledSoftware(void)
{
    HKEY hUninstKey = NULL;
    HKEY hAppKey = NULL;
    WCHAR sAppKeyName[1024];
    WCHAR sSubKey[1024];
    WCHAR sDisplayName[1024];
    WCHAR *sRoot = L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall";
    long lResult = ERROR_SUCCESS;
    DWORD dwType = KEY_ALL_ACCESS;
    DWORD dwBufferSize = 0;

    //Open the "Uninstall" key.
    if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, sRoot, 0, KEY_READ, &hUninstKey) != ERROR_SUCCESS)
    {
        return false;
    }

    for(DWORD dwIndex = 0; lResult == ERROR_SUCCESS; dwIndex++)
    {
        //Enumerate all sub keys...
        dwBufferSize = sizeof(sAppKeyName);
        if((lResult = RegEnumKeyEx(hUninstKey, dwIndex, sAppKeyName,
            &dwBufferSize, NULL, NULL, NULL, NULL)) == ERROR_SUCCESS)
        {
            //Open the sub key.
            wsprintf(sSubKey, L"%s\\%s", sRoot, sAppKeyName);
            if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, sSubKey, 0, KEY_READ, &hAppKey) != ERROR_SUCCESS)
            {
                RegCloseKey(hAppKey);
                RegCloseKey(hUninstKey);
                return false;
            }

            //Get the display name value from the application's sub key.
            dwBufferSize = sizeof(sDisplayName);
            if(RegQueryValueEx(hAppKey, L"DisplayName", NULL,
                &dwType, (unsigned char*)sDisplayName, &dwBufferSize) == ERROR_SUCCESS)
            {
                wprintf(L"%s\n", sDisplayName);
            }
            else{
                //Display name value doe not exist, this application was probably uninstalled.
            }

            RegCloseKey(hAppKey);
        }
    }

    RegCloseKey(hUninstKey);

    return true;
}