PC manufacturer Acer announced on Wednesday a new low-end Ultrabook which will likely resonate with students during the back-to-school shopping season, Mashable reports. Boasting a thin and light design, the lower-end Acer Aspire Timeline Ultra M5 Series measures just .81 inches thin and weighs in at 4.3 pounds. Ultrabooks [1] — which are ultra-slim laptops typically around or under 0.8 inches thick –- have become increasingly popular among manufacturers and consumers, giving on-the-go users a lightweight, full-computer alternative. The M5 Ultrabook comes in 14- and 15.6-inch HD displays, each packing third-generation Intel Core processors (Core i3 and i5 only), a 500GB hard disk drive and the latest in Nvidia discrete graphics. Unusual in an ultra-thin design, the M5 models also have optical drives. The notebooks, which also feature two USB 3.0 ports, tout a full-size chiclet-style keyboard.Those who buy an Acer Ultrabook PC preloaded with Windows 7 (Home Basic, Home Premium, Professional or Ultimate) will be eligible to purchase Windows 8 Pro for only $14.99 (U.S.) through January 31, 2013…