runonce.exe is the Microsoft Run Once wrapper. It is used by the installation programs for third party applications. It allows the installation program to startup again after boot up to give the user the possibility to make further configurations. This process should not be removed to ensure that programs are installed correctly on your system.
runonce.exe is a system process that is needed for your PC to work properly. It should not be removed.
Check your system now to identify unused processes that are slowing down your computer.