I plugged my ethernet in, went into device manager, right clicked ethernet controller, .
OK, there are 104 replies so far, without a clue as to the model number, or the CPU number. If I missed these things being published, I apologize.
My eMachines has the Windows product code on the back, as well as the machine model number on a separate paper sticker, as well as the Model # and equipment RAM, and whatnot, blasted across the front. I obviously realize you may not be so fortunate. But if we had a model number, or you tried a bit harder rto locate device info in the BIOS, we might be able to help more.
It doesn't make sense to me, (although granted it doesn't have to), that eMachines would ship this clunker without a hard wired ethernet controller. The Wi-Fi adapter is a perk, or a "value added feature", which should be in addition to a wired solution.. The Firewire port, as I said earlier, is primarily a video capture solution, and again, a "value added" selling point.
I mean jeez, by your screen cap of device manager, the beast even has a fax modem adapter. (although these were pretty much standard equipment back in the dark ages of eMachine hoards).
I'm thinking either your machine had a separate ethernet card which is now missing, an on the mobo adapter which has failed, or you're somehow simply missing just the driver.
Assuming you have an "Award BIOS", the onboard LAN controller can be enabled or disabled in BIOS. Assuming it exists, you'l find it under "integrated peripherals..