I prepare tax returns for six of my family members. I am retired and do not charge them for preparing the returns. I prepare about 6 returns.

[VolvoGirl]

Here's some more info for you......

How to backup in the Desktop CD/Download program

https://ttlc.intuit.com/community/tax-data-file/help/how-do-i-back-up-my-tax-file-in-the-turbotax-cd...

You should always save both the .tax file and pdf files to an external device or location when you are done.   Like to a flash drive or CD or DVD.

On the Windows Desktop program you have to manually save.  It doesn't automatically save although it should ask if you want to save when you start a new return or exit the program.

VERY IMPORTANT 

Also if you do another return for someone else like your child and their name is the same or similar to yours then it might overwrite your return.  You have to save each return with different names so you can tell them apart.  Like if your name is John and your son is also named John it will save them with the same name so the second one will overwrite the first return.  Go to File-SaveAs and give it a unique name.

[rjs]

Making entries in forms mode will not prevent e-filing. An override of a calculated amount in forms mode will prevent e-filing.

There are a number of entries for uncommon situations that can only be made in forms mode because the situation is not covered in the Step-by-Step interview.

[Critter-3]

Hence my use of the word "may" prevent efiling. 

[johnalletto1]

If you're an experienced preparer some are more comfortable going directly to the form and making the entry directly.  It can save time if you have no questions relating to the return.  I think if I remember correctly, you can always switch back to the interview method and continue the same return.  

[rjs]

Yes, you can switch back and forth between the interview and forms mode.

[VolvoGirl]

Yes you can jump back and forth and jump around and enter things out of order.   With the Desktop program you can do unlimited returns and efile 5 federal for free.   So you can do test returns.  And there is a What-If worksheet you can play with.