@proud_american
Sorry you wasted all that time but am glad you have now gotten it done. This is mainly a user community forum so we can't always tell you the "whys", but can help you get to the right place, which you finally figured out with my steps above. There are a lot of areas where programming and navigation could be improved. Some topics like this one are indeed non-intuitive.
The steps I provided above were for a user using Online TurboTax, so they differ a bit from your desktop software, but the general navigation principle is the same--to get to "Other Tax Situations" then "Other Tax Forms" and then the "W4 and Estimated Taxes" interview. Of course, the method for opening the already-filed return back up is different in Online TurboTax than desktop software.
