Instruction on how to apply the speed.sys driver fix to 
Portdirector NT4. This driver addresses performance related issues 
with the use of FAX programs such as Broadfax.   

First install the Windows for NT4 (PortDirector).  
Replace the old Speed.sys file in the Windows\System32\drivers directory
with the new Speed.sys driver. 
Then reboot NT4 server in order to reload the driver.

This new speed.sys file size is 78.7KB.