Run the UniFi Controller as a Service

[admin]

Make sure you have Java Runtime installed.
Open a command prompt (preferably with Administrative privileges).

Change to the following folder by issuing this command:
cd "%UserProfile%\Ubiquiti UniFi\lib"

To install the Controller as a Service, issue this command:
java -jar ace.jar installsvc

Once done, open Services and start the "UniFi Controller" Service.

[admin]

If you encounter the following error when trying to start the UniFi Controller Service, you need to resolve it by installing the correct Java [bit] version.

Error:
Windows could not start the UniFi Controller on the Local Computer. For
more information, review the System Event Log. If this is a
non-Microsoft service, contact the service vendor, and refer to
service-specific error code 1.

   

I have installed the UniFi Controller as a Service on many different Windows platforms and using different UniFi Controller Versions.
Mostly all my installations are done on 64-bit Windows Servers but some will only work with 32-bit Java and others only 64-bit Java - its hit-and-miss to which one fixes your problem.
My last encounter (a few minutes ago) was on a Windows 2012 R2 Server (64-bit) running 64-bit Java - removing 64-bit Java and installing 32-bit Java solved the problem.

I'm not paid enough to figure out and tell you what version of Java the UniFi Controller wants but it's easier and quick enough to install one version of Java then the other.
PS: I haven't had any luck in installing both versions of Java  - it's either one or the other and not both.