I purchased Intuit turbotax deluxe today and registered the license code. I have completed my returns. Why cannot I not save and file tomorrow?.

If I understand your question correctly:

Yes, you can save your current tax return, and bring it back up tomorrow to file.

1. There is a black banner at the top of the screen.
2. On the extreme left it has a FILE selection.
3. This is not to file your return, but rather is to save your return.
4. Select the FILE button.
5. There are three SAVE options
   1. Save
   2. Save As
   3. Save as PDF
6. In this case I suggest a simple SAVE
7. This will save the file in a format and file name that you can retrieve it in the morning.
8. You will then be able to file the return at a latter date

Please contact us again with any additional questions.

Is it asking you to pay or what is happening?  And be sure you are in the Desktop program and not the Online web version.  That happens a lot.   Does your screen look like the one posted above with the menu items going across the top or are the menu items in a black bar down the left side?  That is the Online version and not the program you bought.  If  you need to switch from online to the desktop program we can tell you how so you don't have to start over.  

You don't have to file until you are ready and hit the big Submit button at the end.