1.5. Upgrading from Earlier Versions of Windows
When you buy Windows Vista, you buy either a full version of the operating system or an upgrade. Ideally, you'd like to upgrade, because an upgrade is less expensive than buying the full version. Only PCs with Windows XP or Windows 2000 qualify for upgrades; users with PCs running earlier versions of Windows will have to buy the full version.
Users who have Windows XP or Windows 2000 and can upgrade will have one of two choices when they do the Windows Vista installation. They can either perform an in-place upgrade or do a clean install. With an in-place upgrade, you install Windows Vista directly over your previous version of Windows, and you'll keep all of your applications, files, and settings just as they were with your earlier Windows version.
If you can't perform an in-place upgrade, you'll have to back up your files and then do a clean install of Vistawhen you do that, you'll wipe out your previous operating system, files, and so on. You will then have to reinstall your applications and copy your files to the PC after the Windows Vista installation is complete.
Whether you're able to do an in-place upgrade depends on your version of Windows XP and Windows 2000, and the version of Windows Vista to which you want to upgrade. Table 1-2 details your upgrade options.