No Upgrade Option When Setup Is Started from Disks or CD-ROM

When you boot your computer from the Windows 2000 floppy disks or CD-ROM to start the Windows 2000 Setup program, you are not given an option to upgrade your operating system. When you start the Setup program in this manner, you can perform only a new installation of Windows 2000.

This behavior occurs because the Windows 2000 Setup program does not support upgrading when you boot your computer from the Windows 2000 floppy disks or CD-ROM.

NOTE: It is possible to boot from Windows 2000 floppy disks or CD-ROM and do a repair installation if Windows 2000 is already installed on the machine. For more information, please see the following article:

To work around this behavior, start the Windows 2000 Setup program from within the operating system you want to upgrade. To do so, run the Winnt32.exe program from the Windows 2000 CD-ROM.

This behavior is by design.

Windows 2000 upgrades the following operating systems:

• Microsoft Windows NT 3.51
• Microsoft Windows NT 4.0
• Microsoft Windows 95
• Microsoft Windows 95 OEM Service Release 1
• Microsoft Windows 95 OEM Service Release 2
• Microsoft Windows 98
• Microsoft Windows 98 Second Edition

This behavior is designed to make Windows 2000 Setup more stable, and provide the following benefits:

• Setup gathers information about services or programs running on your computer that may interfere with Setup and tries to disable them if needed.
• Setup no longer has to search and validate which Windows NT installation to upgrade.
• Before an upgrade, Setup examines your computer to determine if there is enough free disk space, it migrates volume drive letters, and builds a Setup Information File (SIF) to automate the upgrade process.