RedHat 4.8 hangs when booting
 

My server is now hanging when booting ....

Grub loading stage 2 ......
Uncompressing Linux....OK, booting the kernel .....

This is where it hangs. I can boot from CD and run linux rescue but I don't know what to do fix it.

Note: Was running the smp kernel.

RHEL4 is going End of Life (EOL) this month. You might want to think about installing RHEL5 (or even RHEL6 if your apps support the latter).

Try to see if you can get into GRUB and edit your kernel command line. If there's an option that says "quiet" you should disable it (just erase the option from the kernel command line) and see if you can get a useful error message. This is just a bit of a guess, but it might help.