How can I check if NGEN service is running?

Question

I need to use NGEN to precompile my CLR assemblies. I use the queue option to make that the request are processed by the "Native image service".

I need to ensure that the service is running, otherwise I will execute the optimization synchronously.

I tried the following in a Win8.1 x64 machine, and it failed.

C:\>sc.exe query clr_optimization_v4.0.30319_64
[SC] EnumQueryServicesStatus:OpenService FAILED 1060:

The specified service does not exist as an installed service.

Do you know what is the service name?