I had operational and running OES SLES 9 SP2 server until I inserted first installation CD of SLES 8.
I don't know why and how I did it, but by mistake I executed "install_update_rpms.sh" script from the CD and before I could stop it, it installed bunch of rpms from the CD.
Now I can't boot the system.
How can I uninstall those installed packages and replace them with ones from the OES SLES 9 SP2 CD. Using "Rescue linux" boot option? Something else? Please help.

Does the correct install disk have a repair option? It may be able to check the packages and replace the bad ones.

If not, can you boot up in rescue mode, mount your system under mnt and run the rpm command. See if you can list the packages and see which ones are for the other version.

I managed to bring the server up with the original CD and reinstall most of the packages that were installed by the script (list below). Couldn't replace those that are bolded (see below) because I couldn't find replacement on the OES SLES9 SP2 CDs. Should I just remove them assuming that they were never been installed on my system before accident????
Problem I'm facing now is that KDE is not starting. Error that I'm getting when I execute "startx" is: "Could not start kdeinit. Check your installation."
What should I do to fix this issue.

alice-compat-0.21-10.i586.rpm
autoyast2-2.6.36-0.noarch.rpm
bootsplash-1.0-71.i586.rpm
bootsplash-theme-UnitedLinux-1.0-71.i586.rpm
cdrecord-1.11.a28-33.i586.rpm
gnome2-SLES-0.1-24.noarch.rpm
howtodeh-2002.9.6-6.noarch.rpm
howtoenh-2002.9.6-6.noarch.rpm
inf2htm-1.1-630.i586.rpm
k3b-0.7-210.i586.rpm
kdebase3-samba-3.0.3-122.i586.rpm
kdebase3-SLES-8-73.i586.rpm
kdenetwork3-lan-3.0.3-114.i586.rpm
kdenetwork3-lisa-3.0.3-114.i586.rpm
kdenetwork3-news-3.0.3-114.i586.rpm
keramik-20020827-95.i586.rpm
l2h-pngicons-99.2beta8-540.noarch.rpm
listexec-0.5-605.i586.rpm
mhash-0.8.16-30.i586.rpm
mkisofs-1.11.a28-33.i586.rpm
perl-XML-DOM-1.39-35.i586.rpm
perl-XML-Generator-0.91-54.i586.rpm
powertweak-0.99.4-134.i586.rpm
scpm-0.8-54.i586.rpm
sdb_de-2002.9.5-2.noarch.rpm
sdb_en-2002.9.5-2.noarch.rpm
sdb-2002.9.5-2.noarch.rpm
sles-admin-x86+x86-64_de-8.1.0.10-5.i586.rpm
sles-admin-x86+x86-64_en-8.1.0.2-5.i586.rpm
sles-inst-x86+x86-64_de-8.1.0.1-5.i586.rpm
sles-inst-x86+x86-64_en-8.1.0.2-5.i586.rpm
sles-release-8-7.i586.rpm
susehelp_de-2002.09.05-25.noarch.rpm
susehelp_en-2002.09.05-25.noarch.rpm
susehelp-2002.09.05-25.noarch.rpm
susewm-3.6.0-159.i586.rpm
susewm-kcmyast-3.6.0-159.i586.rpm
termcap-2.0.8-625.i586.rpm
yast2-backup-2.6.7-92.noarch.rpm
yast2-firewall-2.6.6-77.noarch.rpm
yast2-inetd-2.6.8-12.noarch.rpm
yast2-powertweak-2.6.14-20.i586.rpm
yast2-profile-manager-2.6.6-55.i586.rpm
yast2-restore-2.6.11-70.noarch.rpm
yast2-runlevel-2.6.16-20.noarch.rpm
yast2-sound-2.6.25-10.i586.rpm
yast2-sysconfig-2.6.14-20.i586.rpm
yast2-theme-SuSELinux-2.6.8-0.noarch.rpm
yast2-trans-bs-2.6.5-12.noarch.rpm
yast2-trans-cs-2.6.27-1.noarch.rpm
yast2-trans-da-2.6.8-11.noarch.rpm
yast2-trans-de-2.6.23-1.noarch.rpm
yast2-trans-el_GR-2.6.6-7.noarch.rpm
yast2-trans-en_GB-2.6.5-1.noarch.rpm
yast2-trans-en_US-2.6.7-1.noarch.rpm
yast2-trans-es-2.6.10-3.noarch.rpm
yast2-trans-fr-2.6.7-3.noarch.rpm
yast2-trans-hu-2.6.12-1.noarch.rpm
yast2-trans-it-2.6.9-3.noarch.rpm
yast2-trans-ja-2.6.30-0.noarch.rpm
yast2-trans-ko-2.6.5-0.noarch.rpm
yast2-trans-lt-2.6.6-7.noarch.rpm
yast2-trans-nl-2.6.12-11.noarch.rpm
yast2-trans-pt_BR-2.6.10-4.noarch.rpm
yast2-trans-sk-2.6.4-11.noarch.rpm
yast2-trans-sl_SI-2.6.6-7.noarch.rpm
yast2-trans-sv-2.6.14-7.noarch.rpm
yast2-trans-tr-2.6.6-7.noarch.rpm
yast2-trans-zh_CN-2.6.12-1.noarch.rpm
yast2-trans-zh_TW-2.6.3-11.noarch.rpm

It looks like your rpm system is working. Use the Verification option and see if any packages are corrupt.

If yast2 works in the console, you can also select installation groups to reinstall kde3.

Found two corrupted packages that were removed. (keramik and susewm)
This helped to reinstall KDE3. Everything is fine now. I'm happy camper again.
Thanks for your great help.