First, are you trying to have a 2.3 installation or a 2.3.4 installation?
To completely remove an Awasu installation:
(*) Run <tt>ResetUi.exe</tt> (to remove your UI settings from the Registry).
(*) Run the un-installer (assuming you used the installer in the first place)
(*) Remove the directory Awasu was installed in.
(*) Remove the local and roaming data directories
Then, to install 2.3, just run the installer EXE. If this is all you want, you can stop here.
If you want to upgrade to 2.3.4, you must first upgrade to 2.3.1, then 2.3.2, then 2.3.3 (i.e. you can't go straight from 2.3 to 2.3.3). It's a straight-forward process, just a little tedious if you have to do so many at once.
What I suspect happened with you is this: when Awasu starts, it checks for a <tt>Awasu.upgrade</tt> file and if it finds one, says you need to run <tt>ADMIN.EXE</tt> to upgrade. This file specifies what needs to be done to do an upgrade so <tt>ADMIN.EXE</tt> processes this file to upgrade everything and if it all works OK, deletes the file so that Awasu will now start.
Now, the un-installer only removes files it installed in the first place, so if you add extra files to the Awasu installation directory, the un-installer won't remove them. I'm guessing you've unpacked a beta ZIP file and then later run the un-installer. It won't delete <tt>Awasu.upgrade</tt> (because it didn't put it there in the first place) so when you re-installed 2.3 again later, that file was still there, hence Awasu complains about you needing to upgrade. This is why step 3 above (delete the installation directory) is important, to make sure everything's gone.