Need help with upgrading Redhat4 to Redhat5

[nivaplei]

Hi, Please help me help me, I am pulling my hair off here!!!
I want to upgrade my server from redhat 4.8 (academic version) to Redhat 5.5, I download the ISO image from redhat.com to a boot DVD.
Then, I boot from that DVD, come to several options such as
1: install or upgrading using graphical
2: Install of upgrading using text command
3: linux updates

I tried all three, and they all lead me to a fresh installation. make me choose between hda and sda, apparently I can only choose hda because the other one will give me an error of fail to mount.
So I pick hda.

All three of the above options lead me to the GUI installation that seems to make a fresh install and wipe out all my data.
Is there something that I miss? Or I am using the wrong version of the redhat boot DVD.

My BIOS version is 1.05 in case it makes any differences.

Please help me with this.
Thank you so much.

Niva

[Irithori]

There is no upgrade path for redhat major versions.

If you have your data on a separate raid or at least partition,
then you can choose advanced partitioning and format *only* your system partitions.
Else you will have to create a fresh backup of your data, install redhat, and restore the data.

A data backup is not a bad idea in that situation anyway.
Other than that, a copy of all relevant configs (net, daemons, etc) and probably logs makes sense.
Some daemons might need a little config tweaking as the versions have changed.