I had the same problem with Win 7 Pro. I went to use ESET to check a downloaded program for any viruses. ESET wasn't in the taskbar in the bottom right corner and selecting the Smart Security Program from the start menu did nothing also. I tried the eset.exe in the program files folder, no luck. I opened the Task Manager and selected the Processes tab with "Show processes from all users" checked at the bottom. There were 3 versions of egui.exe running at the bottom of the list, but they were only running at very reduced memory rates (like 271K).
I opened my "go to" Windows customize program, WinPatrol, and noticed ESET was no longer in the Automatic Startup Programs. I added the .exe back in, saved it and did a restart. ESET was back to operating normally.