+ 1 Votes Avast Security Settings dandaman2234 Updated - 1 year ago SNMP.exe ( short for 'Simple Network Management Protocol') is a process which runs under Windows OS. It provides the facility to gather communication requests from network equipment and redirect the information to a place where it can be analsyed. This can then be utilised by Avast in some form of network usage monitor. As for the usb device not working and Add/Remove Programs missing, this sounds like a security setting (much like a group policy setting) being applied denying you access to install or modify programs on your PC as well as denying access to USB devices that could potentially contain virus'/trojans. You may need to decrease the security level in Avast to enable you to access these feature once again.