Maybe not, still there are a few differences:
1. I currently do not have any previous version of OpenOffice installed
2. I am trying to install OpenOffice 3, not 2.14
I have used programs like CCleaner and Revo uninstaller to check whether there are any OO leftovers on my computer, there seems to be none. I also downloaded the Windows Installer CleanUp Utility, cited in a cross-thread, but when attempting to use it, it says it's a cleaner for Microsoft Office, so I did not use it.
I did have version 2.x of OO installed before, so maybe I'll attempt to install it again and see if that will do the trick and let me install OO3.
OOo 3.0.X on MS Windows Vista