Well, let's be honest shall we....
A emachine is pretty much a disposable pc. Without digging too deep I see that this model goes for around $300.
I'm assuming that you installed the chipset driver for Win7 ( that's the only driver that shows for that OS on the emachines support site).
It is a very real possibility that this system will not be usable with Win7 SP1. It came with Vista originally didn't it?
I have a Dell Latitude D830 that came with XP. The hardware is completely capable of running Windows 7 but the video drivers will not stand for it in any fashion, and there are zero options for that. So, if I want a usable device I have to stick with the original OS flavor.
If this system came with Vista, put Vista back on it and call it a day.