The system partition is the partition that contains the startup files and the boot partition contains the system files (%SystemRoot%\System32).
If you have a separate small system partition for your startup files, generally formatted with FAT, and a larger boot partition, generally formatted with NTFS, a Windows 2000 service pack installation may fail, as it adds 30 MB to the calculation of required free space. If the system partition contains less than 30 MB of free space, the install will fail with an insufficient disk space message.
To workaround this problem:
1. Expand the service pack by opening a CMD prompt and typing:
where n is the service pack number.
2. Copy the updated startup files from the expanded service pack folder to the system partition.
NOTE: This procedure works because update.exe will NOT find any startup files that need to be updated, so it will NOT add 30 MB to the freespace requirement on the system partition.
NOTE: If you system partition contains Ntbootdd.sys, this is a copy of your SCSI controller driver, used if the the controllers BIOS is NOT enabled. To update Ntbootdd.sys, copy the driver from the expanded service pack folder, delete Ntbootdd.sys, and rename the driver as Ntbootdd.sys.