On Windows Vista, the name displayed for the native image service is "Microsoft.NET Framework NGEN v2.0.50727_X86" or "Microsoft.NET Framework NGEN
As far as I know Windows Server 2008 is built from the same code base as Windows
Vista, so I think your service is this service.
"The native image service is a Windows service that generates and maintains native images. The native image service allows the developer to defer the installation
and update of native images to periods when the computer is idle."
Also, please read this
"Normally, the native image service is initiated by the installation program (installer) for an application or update."
"After being initiated by the execution of an Ngen.exe command that includes the /queue option, the service runs in the background until all actions have
been completed. The service saves its state so that it can continue through multiple reboots if necessary.
When the service detects that there are no more actions queued, it resets its status so that it will not restart the next time the computer is booted, and then it shuts itself down."
So please first tell me what you really want to do with this service, if it is not used by any software(installer for example). The service will shut itself down.