Some PowerBook 165 systems were shipped with two different enablers:
* version 1.0.2 on the hard drive
* version 1.0.3 on a floppy
Version 1.0.2 is the problem. The solution is to replace it on the hard drive with version 1.0.3, which works properly with the PowerBook 165 and Express Modem.
In general, Apple recommends using the latest version of an Enabler. If you get the message "The Express Modem cannot be used with this PowerBook" you should compare the version of the Enabler installed in your Macintosh's System folder to the version of the Enabler that comes with the Express Modem software -- and use the later of the two. Here's how:
1) Drag the old Enabler out of the System Folder (but not into the Trash).
2) Drag the new Enabler into the System Folder.
3) Restart.
4) Throw away the old Enabler.