What should I do when I did something wrong with my Mozilla's update?

This is just happen recently when an information about the latest Mozilla update suddenly pop out from my window. It says that I can update mozilla 3.6.9 and I click that button which take me to a tab that allow me to update mozilla firefox. When I begin to install suddenly it says that I need to update my Adobe flash player first,I did that,go to the provided link and download my Adobe but it requires me to turn off mozilla and after I turn off and turn on my mozilla again I can’t come back to the update tab of mozilla that I’ve visited,previously.

So I just get in to the main site of mozilla and I see there’s a button than suggest me to install mozilla 3.6.9,I click on it and have finished the installation but I feel that it didn’t update my existing mozilla 3.6 but rather install the new separate version of mozilla in my pc (there are two separate data for mozilla).

I check the FAQ page about update category and it said that it doesn’t matter if I install (not update) the newest version of mozilla firefox, it will still run the same program but with newer application. It’s not like that! I have two separate data for mozilla,one is 3.6 and the other is 3.6.9.

So how could I fix this issue? Should I delete my existing mozilla data? And if the same issue happen again how could I find the same tab that allow me to update mozilla if I miss the announcement?

Sorry if this is a bit longer for this simple issue,I kinda like to elaborate more about this issue. And thank you for your time.