The Event Viewer is just a viewer to see what events and errors have occurred, listed by date and time.
It has several sections, as listed in the left panel.
network disconnects should be listed in the "System" section, so click that.
Allow time for the centre panel to populate (many events may take a while to populate).
It helps if you expand the window to fill the screen so it's easier to read.
The centre panel is where all the events are listed for a chosen section, in chronological order.