rapimgr.exe is a process associated with the ActiveSync software from Microsoft. ActiveSync is a software used to synchronize data on your PC with a mobile system such as a pocket PC or a mobile phone.
It is important for the ActiveSync function so should not be removed.
Non-system processes like rapimgr.exe originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that over time your registry suffers fragmentation and accumulates invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues