I have Word 2010 and Word 2013 on the same computer, and have never had a problem with the operation of either program till now.
I can use "Alt + left click + drag" to select a vertical block of text in Word 2010. But I can't do so in Word 2013. I used the same wireless keyboard and wireless mouse, and verified this six different ways. I know I need to select more than one column. In Word 2013, it looks like I the program is tring to select horizontal lines. Horizontal lines become highlighted and not highlighted at a very rapid rate.
I don't own a wired keyboard or mouse. If I am able to obtain them, I will try that as a possible solution.