When you read Unattened.doc, from the Deploy.cab file in the Support\Tools folder on the Windows 2000 CD-ROM, the information about the ComputerName key in the \[UserData\] section of the Unattend.txt file is for a clean install of Windows 2000.
When performing an unattended upgrade, the ComputerName key will product different results, depending on which operating system you are upgrading.
If you are upgrade from Windows NT 4.0 Workstation, the ComputerName key had no effect. The name of the Windows 2000 Professional computer will NOT be changed, regardless of what you set the ComputerName key to.
If you are upgrading from Windows 95 or Windows 98, the presence of any value in the ComputerName key will cause Setup to generate a random name for your computer. If you wish to keep the same computer name, do NOT include the ComputerName key in the answer file.