If you can't even log in, you need a rescue CD or floppy disk. Maybe the original Redhat CD can be used - it should give you an option to start up in rescue mode. Once you have the machine running you can mount disk partitions and remove the files that Intel kindly supplied.
Then you might want to install the ALSA sound drivers, maybe according to the instructions at
http://freshrpms.net/docs/alsa/
I'm sure your sound chip is supported.