I am not sure why you are having a difficult time running the database tuner. Most upgrades require a database tuner given the upgrade now has new tablets, etc. and needs to match your older data.
Any time a database tuner is needed, it will be provided by AC to download along with the new program. I am not sure why, but it is recommended to be run from within the AC folder. You should also right-click on it and Run As Administrator. After that, it should be rather self-explanatory as to the next few steps.
HTH.
