The default behavior of Windows 2000 is to warn the user, who can then decide to continue or abort the installation.
You can use the Code signing for device drivers Group Policy at Computer Configuration\Administrative Templates\System or User Configuration\Administrative Templates\System to set the policy to:
Ignore - No warning, the installation proceeds.
Warn - The default behavior.
Block - The installation stops with none of the files in the installation package being installed.
NOTE: You can also use Control Panel / System / Hardware / Driver Signing.
If the policy is Not configured, you can set the Policy value name, a REG_BINARY data type, at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Driver Signing or HKEY_CURRENT_USER\SOFTWARE\Microsoft\Driver Signing to:
00 - Ignore.
01 - Warn.
02 - Block.