Copyright Goodheart-Willcox Co., Inc. 64 Computer Service and Repair and those with the letter N affi xed to the edition name. Th e Starter edition is limited to emerging countries and not sold as a retail copy in the United States. Only an orig- inal equipment manufacturer (OEM) may purchase the Starter edition and install it on certain minimal systems, such as tablets. Th e Enterprise edition is not avail- able for retail purchase and can only be sold through the volume-licensing program. Volume licensing is when multiple copies of the operating system are sold to a large consumer, such as a corporation, government, or educational institution. It allows multiple copies of the same operating system to be installed using the same activa- tion key and is based on the number of users or workstations in the organization. Th e Professional and Ultimate editions are also available through volume licensing, but not to the general public or OEMs. When you see the letter N affi xed to the name of the version, it means the operating system does not include Windows Media Player or Movie Maker. Figure 2-23 lists the Windows 7 system requirements. Not all versions of an operating system are upgradable. For some editions, you must back up all important fi les and then install the new operating system. During the installation process, all existing fi les are destroyed because the new operating system deletes existing fi les and replaces the old operating system. When perform- ing an upgrade, the new operating system preserves existing user fi les such as doc- uments, pictures, and movies. Even the old operating system is typically saved in a folder identifi ed as OldWindows. Saving the old operating system will usually allow the installation of a new operating system to be reversed if something goes wrong. It is best to back up all important fi les before installing a new operating system, even before performing an upgrade. Th ings can go wrong, and valuable fi les can be lost. An important note to consider is that, as of this writing, Mainstream Lifecycle Support for Windows 7 has ended. Additionally, extended support will end in the coming year. Th is means Microsoft will no longer provide security updates or sup- port for PCs running Windows 7. Windows 8 Editions Windows 8 is available in just four editions: Windows 8, Windows 8 Pro, Windows 8 Enterprise, and Windows 8 RT. Windows 8 RT edition is designed especially for portable devices, such as tablets and phones. Other editions are designed for devices with more resources such as a powerful CPU and lots of memory. Installation re- quirements for Windows 8 are listed in Figure 2-24. Windows 8 will run on 32-bit or 64-bit systems and on an ARM device. ARM devices are also referred to as advanced RISC machines. Th ey are typically portable devices with limited computer resources and are designed for very little power con- sumption so that the battery lasts as long as possible. ARM is used in devices such as smartphones, tablets, iPads, and some gaming devices. Some tablets use processors other than ARM, such as the Intel Atom. Hardware 32-bit 64-bit CPU 1 GHz 1 GHz RAM 1 GB 2 GB Hard drive space 16 GB 20 GB Graphics support DirectX 9 and Windows Display Driver Model (WDDM) 1.0 DVD drive Required for installation or upgrade using a retail version of the operating system Goodheart-Willcox Publisher Figure 2-23 A computer must meet the minimal requirements to install Windows 7.