If your Windows NT Server 4.0 systems have mirrored drives, be aware of the following upgrade gotcha. We have several servers running NT Server 4.0, and we want to upgrade them to Windows 2000 Server. However, each server has at least one pair of mirrored drives, and Win2K Server doesn't support this configuration. To maintain our infrastructure, we must migrate to Win2K Advanced Server at several times the price of the migration to Win2K Server.