Unfortunately, my memory for those units is a bit fuzzy at this point, but from what I remember, pretty much everything you need should be on the download site (minus any licensed software for DVD playback or CD burning which would come on separate disks).
Not sure if it can help, but if you haven't installed those other ATK-related files under the 'utilities' section, consider giving those a try if you have the time and interest and confirm at least the brightness and volume keys work along with the onscreen display (which probably isn't related to the keyboard issue though).
Just wanted to confirm the keyboard lights worked before the reinstall and from what I remember, the keyboard lights on those earlier models flash momentarily at power up if you can verify this to make sure the hardware is working okay.
Unfortunately, don't have a copy of the driver disk around, so hopefully others are able to help with this if it's necessary, but not so sure that it would really make a difference this time. Thanks.