MB_SERVICE_NOTIFICATION is used for a service application.
Please check your DCOM server's Runas setting by DCOMCnfg, you can set it to run as interactive user, then your server will run in winstation/desktop that can interactive desktop. This way you should be able see the dialog
Another way is set your server to runas some account, then it will run in a non-interactive winstation/desktop, you can programmatically switch your server to interactive winstation/desktop before displaying the dialog, however as the above post already said, using UI in DCOM server is not good practice.
开发服务程序(ATL服务),编译后,用 /service开关运行服务,通常,服务程序是运行在另一个桌面系统(Windows 系列是多桌面的,但只有一个是可见的),为使你的界面出现在当前桌面,必须在服务管理器中将其设置成可与当前桌面“交互”,如果你的Server 是Window2000,请在开始菜单中选择程序组“Administrative Tools,中文版为:管理工具”中的“Service”,此时会出现服务管理控制台(Microsoft MMC界面),检查你的服务是否列在其中,如果没有,请用/service注册你的服务,然后步骤同上,找到你的服务后,双击鼠标,会出现一个关于此服务的“属性页”,选择“Log On(中文版对应什么?,忘了!)”页,会出现“Local system account”,下面的选项是:“Allow service to interact with desktop”,选中即可,重新启动服务后,你的界面即可出现