Thanks folks. I'm using Windows XP.
I did get this problem resolved. Someone gave me this link.
Setting XP to Use 24-Hour Clock Obsessed with the Press
That got me the 24 hour clock, and got rid of the AM/PM, but it was still on three lines. Then, I found this second link.
TClockEx - Taskbar Clock Enhancer
This got everything back on one line, like I wanted it. Upon looking back, I could probably have done it with just the second link.