I have always thought that "with regard to ..." is correct but a lot of people use "in regards to ...".
Am I correct?
To my knowledge, with regard to is the appropriate, i.e., standard choice. It seems that "in regards to" is one of many examples that language is living and evolving, though not always for the better.
We had it drilled into our heads that "regards" was a salutation and "in regard to" was proper for direction to a subject. So it is disturbing to hear it misued commonly, today.