Are you trying to upgrade or fresh install? I read of issues upgrading from previous OS... if it is a fresh install, check your downloaded ISO image against the hash details. you can download and install this HashTab tool to quickly find file hash information and it will just appear when you right click - properties the ISO image.
i did try an upgrade n den i tried a fresh install bt had d same problem on my acer laptop which i bought few months ago .. den i installed it on ma hp desktop which i bought in 2010 n its perfectly workin in it but cnt install it on ma acer laptop ..
I've installed W8 X-64 --currently Enterprise R8 RTM from TechNet on two different Acer models -- no problem - I'm currently using an ACER Aspire V5 -171 (the small 11.7 inch one - brilliant for travelling - decent enough resolution so Photoshop etc can run, Fast USB3 port, HDMI output, intel HD graphics) and cheaper than some tablets. !!! The I3 processor is sufficient for a mobile laptop giving adequate performance and decent battery life and with 8GB RAM and an SSD it makes many desktops seem slow)
The W7 USB3 driver needs updating -- Windows 8 USB3 driver from Ms installs automatically. Otherwise use any drivers that need to be installed from the ACER site --the W7 ones all work apart from the USB3 driver. You'll probably need your LAN / wireless driver, the Intel high speed storage driver and the Card reader then everything is fine.