Microsoft has released what will likely be the last major update for Windows2000 for some time. There are no new service packs planned for Windows2000, as its support is nearing EOL. Apparently, even if you've been automatically updating your Win2K installations, you should still install this update, as there are several fixes that haven't been included in the security updates.

"Update Rollup 1 for Windows 2000 SP4 was released June 28, 2005. This update rollup contains a list of security-related updates produced for Windows 2000 between the release of Windows 2000 SP4 and April 30, 2005. April 30, 2005 is the date when the contents for Update Rollup 1 were locked down for final testing by Microsoft, external beta testing sites, and customer sites."