Here's the deal. It's complicated.
In 2004, they released the 2004 update. it had 5 courses. Halfway through the year, they sold an update called 'eXtra', that added two courses to the 2004 hard drive.
When you updated it to a 2005, if you already had the 'eXtra' kit, it added 5 new courses and kept the two extra courses.
When it called in and updated the machine, it marked the pcb to run either 5 or 7 courses depending on how you were set up.
So, now, lol, if you get a 2005 hard drive, you can get either a 5 course hard drive, or you can get a 7 course hard drive. If you get the 7 course hard drive but only have a 5 course board, it will only play the 5 courses.
So long story short, it's on the PCB, but you might want to try plugging the 7 course hard drive into the 5 course board just to make sure somebody didn't put a 5 course hard drive with it at one time.
Whew.