When you try to get the new GigE network cards running in a RedHat 9 (RH9) install, as well as on Fedora Core 1 (FC1), the driver can get the NICs initialized and recognized. This is because the PE750 has newer Intel Pro/1000 onboard NICs than what the RHL9 and FC1 kernels include. First, if you can, try upgrading to the very latest available RHL9/FC1 kernel, now available through Fedora Legacy, that should solve it.
Since you don’t have a working NIC, this upgrade might be too difficult. You can also get the driver from the e1000 SourceForge site (www.sourceforge.net/projects/e1000/) and put that on a floppy. You’ll need a kernel or driver that was released in or after November-December 2003.