I've installed 9.2.2 on my 2400c. It seems to work well. Networking may be a bit faster, but I didn't run 9.1 long enough to be sure. The main reason I did it was to install the latest version of Airport, but I ended up having to use the Tomeviewer method anyway, so I think it could install under anything. The process is kind of involved. The patch for the 9.2.1 updater is broken, since Apple changed the disk image somehow. If you're going straight to 9.2.2, you need to do one of three things to get an intermediate installation of 9.2.1 on the target drive: 1. Install the drive in a supported machine and run the updater. 2. If your HD is small (<8 or 4GB, I can't remember) you could use SCSI disk mode to accomplish the same thing from a supported machine. 3. Fool the installer into thinking you have a supported machine by changing the mach ID to a supported machine with Gestlab or a similar programmer's tool. Needless to say, don't boot the 2400 from the intermediate installation of 9.2.1. You should probably be using a separate partition, but I managed to update my only one without a second machine by booting from CD. Once you've upgraded to 9.2.2 (with the patched updater), you'll need ResEdit to copy and paste resources into (a copy of) your system file, from the files in this archive: ftp://ftp.gps.caltech.edu/pub/kby/Old%20World%209.2.x/9.2.2%20Patch%20Archiv e.sit You'll also need to install the sound extension from that archive and disable the one that the updater installed. Don't install anything from the Non-OF folder. The data fork patch doesn't appear to work. There's a free support forum here: http://www.macfixitforums.com/php/showflat.php?Cat=&Board=OS92&Number=312639 &page=0&view=collapsed&sb=5&o=7&part=2 You may be better off waiting for the next update of the Helper app, which promises 2400c support, but so far I've had no problems. The inability to install the data fork patch is worrying however. Ed