Did you check this page: https://docs-v4.mango-os.com/windows-installation
Are you seeing any errors in eventviewer that you can share?
I just found out the reason. Of course I follow above instruction but instead of installing mango in C drive, I created a folder named SCADA in C:\Program Files\ and have mango and mango_data folder in SCADA folder. Maybe the name Program Files is not easy to identify with windows services. This should be added in the instruction.