I've struggled with this because the instructions on page 22 of the user's guide don't go into detail about how to do it. It helps a lot if you know what all of the icons stand for. If you're like me you'll need a handy copy of the page showing them all. Any page numbers referenced are for the User's Guide. It's a free download on Minelab's website. The following is how I did it and so far is the most painless way how to do it.
I wanted to set up Mental Metal's coin program on my 900. Look for his channel on YouTube. The first thing I did was do a factory reset of the machine. A long press of the power button while the machine is off and wait for FP to be displayed (p. 60). A total of 8 custom programs can be stored on the 900. One each on Park 1, Park 2, Field 1, Field 2, Beach 1, Beach 2, Gold 1, and Gold 2. I chose to start in Park 1. Put your machine in detect mode in Park 1 and long press the user profile button. That's the lower of the two buttons on the right side of the control box. Make sure that you see the user profile icon in the upper right corner of the screen (P. 8, item 10). What you've done is clone Park 1 in the user profile setting. Now you can make changes to any local setting (P.16) while in user profile mode that you want to and it will automatically be saved. That's it, you're done. You can now toggle between your custom user profile and Park 1 by a short press of the user profile button. You can make custom user profiles for the remainder of the search modes for a total of eight.
I wanted to set up Mental Metal's coin program on my 900. Look for his channel on YouTube. The first thing I did was do a factory reset of the machine. A long press of the power button while the machine is off and wait for FP to be displayed (p. 60). A total of 8 custom programs can be stored on the 900. One each on Park 1, Park 2, Field 1, Field 2, Beach 1, Beach 2, Gold 1, and Gold 2. I chose to start in Park 1. Put your machine in detect mode in Park 1 and long press the user profile button. That's the lower of the two buttons on the right side of the control box. Make sure that you see the user profile icon in the upper right corner of the screen (P. 8, item 10). What you've done is clone Park 1 in the user profile setting. Now you can make changes to any local setting (P.16) while in user profile mode that you want to and it will automatically be saved. That's it, you're done. You can now toggle between your custom user profile and Park 1 by a short press of the user profile button. You can make custom user profiles for the remainder of the search modes for a total of eight.