I have read of people doing this with poor results. 8 is a "circus". Designed for the "touch" type of computer. It is a learning curve all over again just like Windows 7 was. My suggestion is, try to get back to the retailer you bought it from, if you are unhappy with the OS. Strike up some kind of a deal, to exchange the system for what you want. Computers are delivered to retail stores w/o a OS installed. This is done by their tech personal. Best Buy I have been told is one.
I am not a computer guru, but I believe it would be possible. However be smart and seek out at person that makes his living setting up computers. PC scooter also echos my advice. Be smart and save yourself heartache.
Yes it can be done. However it requires much work and expertise. My advice is learn windows 8 first. All OS's from Microsoft are similar. Once u know it , u can run it in the desktop mode and it similar to 7. Then if u still want 7, make the change. It requires some expertise and a lot of time. I think u should get someone who knows how to do it. Or the dealer might do something .. I have win 7 and 8 on a new laptop. So I use both.