The helpsvc.exe file is installed and used by Radium. You have to delete helpsvc.exe immediately after you have found it. The parasite will continue to violate your privacy and harm your computer unless helpsvc.exe and all related objects will not be completely removed from the system.
If you have difficulties erasing the file, consider using an anti-spyware program.
In some cases the presence of helpsvc.exe does not mean that your system is infected. This file may actually belong to Microsoft help service, which is a fully legitimate application and therefore must stay intact. If you are in doubt, please scan the helpsvc.exe file using you regular spyware remover or antivirus program.