YEA....
umm...urr....i wish i was in a better place so i could better describe to you the step by step, steps involved. Butt...basically you have to set the host (emachines) for internet connection sharing. (ICS). so...goto your network connections. double click your local area connection, then select properties. Now open the advanced tab...and there you should see share internet connection. just check it.
now that ICS is enabled lets go into your wireless connection properties on the host computer (emachines). which is done the same way as described above. once in the wireless network connection properties window select the wireless networks tab. if you see any connections in the "preferred networks" window. select them and remove them. Next, click the Advanced tab at the top of the window. Select Computer to computer (ad hoc) networks only and clear the Automatically connect to non-preferred networks box if it is selected
now....Click the Wireless Networks tab again. Under Preferred Networks, click Add. also, In the Wireless Network Properties dialog box, specify a Network name (SSID).
now on the client computer (the acer). goto the wireless network connections properties, just like we did before on the emachines. goto the wireless networks tab. refresh the list of available networks, and select the ad hoc network you named and configured previously from the list.
This, im sure will require a bit more tweaking....but basically this is what to do. Like i said, due to where i am...its a little hard to think of exactly step by step what to do. this should get you alot closer than you were before....
Good LUCK!