Thank you for the two comments above. Unfortunately, neither address the issue as I was needing addressed.
I did find the following AWS documentation, which is specifically noted by AWS as "Computing Basics for Windows", but in bullet pt# 4 of this "Step 4: Launch an Instance" page there is the clarification that you must first press LAUNCH before the Key Pair setting is requested of you. Nowhere else in their documentation was this specified, which was the confusion for me: I didn't want to press LAUNCH without first selecting the Key Pair but in fact that's a required step. Here's the URL:
http://docs.aws.amazon.com/gettingstarted/latest/computebasics/gettingstarted-launch-instance.html
I hope this clarifies confusion for someone else in the future.