hpzev4wn.dll is a hpcevt06
belonging to HP Doc Event Dialogs
from Hewlett-Packard Corporation
Non-system processes like hpzev4wn.dll originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that your registry has suffered fragmentation and accumulated invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues.