Okay andox, this is what I would do:
1.) Get yum if you don't already have it. here's a link for Red Hat 9.0: http://ftp.freshrpms.net/pub/freshrp...rh.fr.i386.rpm
Use "rpm -ivh yum-2.0.4-1.rh.fr.i386.rpm" to install yum.
2.) After yum has been installed issue the following:
This will take about 15 to 20 minutes, maybe even more.
Once upgrading has finished you can restart linux. Then at the GRUB boot-loader you'll see two options of linux:
This way you can try installing the winmodem shit by using the new_kernel_version and in case there are any problems you can still use the old_kernel_version. Get the drift?
Here's some more info that might help:
Hope this helps!