Well, I removed nvnet module and uninstall the NVIDIA_nforce-1.0-0248.rh73up_2.4.18_3.athlon.rpm, the X windows still hang forever.
I removed NVdriver and uninstalled two corresponding rpms, and reinstall the two rpms. Same problem: X windows hang forever!
Then I UNPLUGED ZIPDRIVE from USB port. I notived the NVdriver is unloaded every time the machine booted. Would someone tell which config file is responsible for unloading the NVdriver?
I ADDED /sbin/insmod -f NVdriver at the end of /etc/rc.local
The X windows back to work! At this point, I installed NVIDIA_nforce-1.0-0241.rh73up.athlon.rpm instead of previous 0248 rpm. The network back to work!
So far both X windows and network work fine. I guess the pluged zipdrive and configuration of the Northbridge and Southbridge cause A7N266-VM failed, but don't know what were failed exactly. Could someone point out how to trace the problem?
Hope the workaround could help others. Thanks bwkaz,