Somehow I managed to get both Suse 10.0 (commercial version), and OpenSuse 10.2 simultaneously installed on my system. Presumably, I should have removed 10.0 before trying to upgrade. Anyway, I now have 10.0, 10.2 and Windows 2K on the computer. I need to uninstall at least one of the Suse versions, but can’t seem to find any info on doing it. Lots of stuff about installing Suse, but nothing about UNinstalling it! YasT will apparently let me remove various packages, but I couldn’t find an option to remove the whole operating system. The installation CD didn’t include that option, either. I’m sure it’s something very simple, but I can’t seem to find it.
Well, uninstalling is easy;
Startup with the version you want to keep and run YaST > Partitioner in that.
There you can simply delete the partition with the openSUSE you don’t want anymore (make sure it’s the right one! 
)
The freed space can be then used to create a new partition (like a separate /home) or to extend an existing partition.
As always when playing with you partition layout : MAKE SURE YOU HAVE A BACKUP OF THE DATA ON YOU DISK (including the data on windows) THATS IMPORTANT TO YOU!!
Sorry for the caps 
When you’ve done this open YaST > Boot loader , and there you can delete the entry for booting to the other, now removed, SUSE version.
Hope that helps,
Wj
PS Adler, nice to see you back! Hope you stay & enjoy.
But it’s not nice to ‘hijack’ a new members post for this! 
I followed your instructions, but I have another problem!
I identified the partition I wanted to remove (hda5) by watching as the grub loader came up. Then i went into 10.0, Yast>partitioner, and deleted it.
When i tried to reboot, I get “GRUB loading, please wait…” followed by “error 22” and a black screen. Am i going to have to run a low-level format and reinstall Windows as well as Suse?
Use the repair facility from the install disc to repair grub.
Hmm… that was unexpected, but as FeatherMonkey states you can fix this by booting into repair mode with the install media.
I think this is due to your partition names shifting (e.g. /sda2 went to /sda1).
After running the grub reapir you should be ok!
Sorry for that… :o
Why not install 11 in the empty space and let the install reconfigure grub?
Or, configure grub manually during the install, or, fix it later on.
I think having done what you have done you ought to let 11 manage the boot process (as 10.0 did previously).
Just trying to save you some time. Either way you will jump through the same hoops.