Anybody know how I can go back from Windows 10 Pro to Windows XP PRo?

Buy a copy of XP Pro with a product key; back up any files you want to keep; install Windows XP Pro; reinstate the files you want to keep and replace the programs you want to use (some of your current programs may not work in XP); install XP Pro drivers for ancillaries (if available). I am currently reluctantly moving away from Windows XP because it does not support USB3 (not at full speed) and because my internet access is so slow when using XP. I am told internet protocols have moved-on and are no longer optimised for XP. Also my bank will not allow internet banking via XP platforms after this month. If you search on-line, you will find free copies of XP Pro together with the code you need to activate them. They can't be legal, but they work.

The correct answer is "You probably can't". New hardware seldom, if ever, make drivers for older OS's. XP would have no clue how to run the video, network, etc. If you need XP for an old program, use a virtual box on your windows 10 device instead.

1st save all you wish to use on usb flash, then wipe drive then install xp, you cannot just go back from 10

Format the hard drive or a partition and install Windows XP Pro.

Format the hard drive

Install the software.

There is no formal downgrade path to xp