DevxExec is a command-line tool that allow to run processes from another user account credentials. Its actually not really important if your service runs in interactive mode or not. You always can specify window station and a desktop while creating a new process. There is a special parameter in StartupInfo structure for this. You also can use DevxExec to run a process from the windows service under another user.

The license of this software is Freeware, you can free download and free use this system utility software.