CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [222]
Clean Installation
A clean installation usually begins with a completely empty hard disk. The advantage to doing a clean installation is that you don’t carry problems from the old OS over to the new one, but the disadvantage is that you have to reinstall all applications and reconfigure the desktop and each application to the user’s preferences. You perform a clean installation by resetting your CMOS to tell the system to boot from the optical drive before your hard drive. You then boot off of a Windows installation disc, and Windows gives you the opportunity to partition and format the hard drive and then install Windows.
Upgrade Installation
In an upgrade installation, the new OS installs into the same folders as the old OS, or in tech speak, the new installs on top of the old. The new OS replaces the old OS, but retains all saved data and inherits all of the previous settings (such as font styles, desktop colors and background, and so on), hardware, and applications. You don’t have to reinstall your favorite programs!
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TIP Before starting an OS upgrade, make sure you have shut down all other open applications!
To begin the upgrade of Windows, you must run the appropriate program from the optical disc. This usually means inserting a Windows installation disc into your system while your old OS is running, which starts the installation program. Then, to do an upgrade, you indicate that the new version of Windows should install into a directory that already contains an installation of Windows (it will do this by default). You will be asked whether it is an upgrade or a new installation; if you select new installation, it will remove the existing OS before installing.
If for some reason the Windows 2000 or Windows XP installation program doesn’t start automatically, go to My Computer, open the installation disc, and locate WINNT32.EXE. This program starts an upgrade to Windows 2000 or XP. In Windows Vista, open the disc in Windows Explorer and run Setup.exe in the disc’s root directory, which starts the Vista upgrade.
Multiboot Installation
A third option that you need to be aware of is the dual boot or multiboot installation. Both Windows 2000 and Windows XP can install in a separate folder from your existing copy of Windows so you can put both operating systems on the same partition. Then every time your computer boots, you’ll get a menu asking you which version of Windows you wish to boot. Multiboot requires that you format your active partition with a file system that every operating system you install can use. This hasn’t been much of a problem since the Windows 9x family stopped being relevant, because there’s really no reason to use anything other than NTFS. Windows Vista doesn’t let you define its install folder, so to multiboot Vista and XP, for example, you’d need to install each OS on a different partition.
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NOTE When configuring a computer for multibooting, there are two basic rules: first, you must format the system partition in a file system that is common to all installed operating systems, and second, you must install the operating systems in order from oldest to newest.
Other Installation Methods
In medium to large organizations, more advanced installation methods are often employed, especially when many computers need to be configured identically. A common method is to place the source files in a shared directory on a network server. Then, whenever a tech needs to install a new OS, it is a simple task of booting up the computer, connecting to the source location on the network, and starting the installation from there. This method alone has many variations and can be automated with special scripts that automatically select the options and components needed. The scripts can even install the necessary applications at the end of the OS installation—all without user intervention once the installation has been started.