ashdisp.exe is a process belonging to Avast Internet security suite.
This utility forms an important part of your computers protection against Internet-bound viruses and worms, and should not be terminated.
Non-system processes like ashdisp.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