slrundll.exe is installed alongside the driver for Smart Link's range of communications hardware. This should not be removed where modem and Internet connection stability are concerned, although not a critical system process.
Non-system processes like slrundll.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