The Energy Star rating is given out to appliances that meet or exceed certain standards for reduced power consumption. You may have seen the star on your television, Washer and dryer, and even your digital converter box. Not every appliance and definitely not every computer has achieved this rating. So how do you find the ones that have the rating?
If you go to the major online stores (BestBuy, Newegg, Frys, Walmart, and CDW are just a few examples) you'll find that they don't advertise which computers are environmentally friendly. In fact, you will have to search for Energy Star just to find their products. At Best Buy, they only advertise laptops, monitors, and printers which have the Energy Star rating. Newegg has a few monitors and printers. And CDW has one printer that comes up in the search results. At Walmart, they have hard drives, a couple of printers, and monitors that are listed as Energy Star rated. And Fry's has nothing listed in computers.
Finding the Energy Star rated computers at a physical "brick and mortar" store would be a little easier. You will have access to the sales people and the actual computers and their boxes. The computers will have the Energy Star symbol located on them. And the sales people should be eager to point out the environmentally friendly products.
ENERGY STAR Website
The easiest way to find out what brands have the Energy Star rating would be to go to https://www.energystar.gov and search their lists. From their homepage, you will go to Products -> Office Equipment -> Computers. There, you have the option of searching their list, finding a store which sells Energy Star rated computers, and even special offers on the computers. The site also gives you information about what it means to earn the energy star.
Along side the Energy Star website, you can check EPEAT at https://www.epeat.net/. The EPEAT site states that it is Green Electronics Made Easy. They rate the equipment by Bronze, Silver, and Gold. From their homepage, you can click on the numbers under each system to find the manufacturers and models that meet that standard. This is probably the best "one stop shopping" place for your EnergyStar needs.
https://www.cdw.com/shop/products/default.aspx?edc=1403427&enkwrd=ALLPROD:Energy+Star CDW's search results for Energy Star
https://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=Energy+Star&x=0&y=0 Newegg's search results for Energy Star
https://www.bestbuy.com/site/olspage.jsp?id=pcmcat149900050024&type=category&searchresults=1&searchterm=energy+star BestBuy's search results for Energy Star
https://www.energystar.gov/index.cfm?fuseaction=find_a_product.showProductGroup&pgw_code=CO Energy Star's Computer Search page
https://www.walmart.com/search/search-ng.do?search_query=Energy+Star&search_constraint=3944&tc=0&ic=48_0&ref=+125875.126085&tab_value=12_All WalMart's search results for Energy Star narrowed down to Computer-related items (You may have to copy and paste this into your browser manually)