This Emachine link leads me to think that your system has an intel made board in it.
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So downloading the INF update file from this link will get your chipset updated.
Intel download
The emachine link says that your system would have an intel 801 sound chip in it. Intel doesn't list that as a download item from them. But my guess is that when you installed the inf utiliy, and found out what chipset is onboard, which my guess would be 810, you could download an intel model 810 based motherboard driver and get that to work. Whatever motherboard you choose to try drivers from would also list video drivers.
This link shows the various boards.
Intel motherboard list
You might need to pull the modem out and look at the numbers on it, and do a google search, to figure out where to locate a driver, if you can't find it from emachines site.