Both DAX won't work cause they are not excluding the rows where I have one user who took one training and complete for example 30% first time but 100% second time.
Just to give you example: For Training 1: User 1 first watched 30% of the training, but later he watched 100% of the training.
So when doing the count for non completed training, he needs to be excluded.
With you DAX, he will be included.
The logic that should be applied by DAX is to count rows where % Complete is less than 100% and ignore any rows If the a user has another row where % complete is 100% in addition to value less than 100%.