Have you deleted the log files, system event files, and other files you can delete. You didn't mention what version BCM 400 you have. If it's a 3.7 and below its WinNT. Version 4.0 and above is linux. Since Nortel has been acquired by Avaya, their tech support website is a mess. If you have access to TSB of BCM product there are instructions on how to delete files.