Format Hard Drive & Clean Install of XP Pro

My laptop's performance has been rapidly deteriorating. I would like to
remove whatever is causing the problem & reinstall from the original XP Pro

I've been told the disk will do a clean install, but will it remove all
files without saving or backing them up? Would there be any benefit by using
the right-click "Format" option on the C drive in Windows Explorer first, or
any other procedure first?

I have reinstalled the manufacturer's original image disk several times, but
there's no improvement.

Am I correct in assuming the XP Pro installation disk is all I would need?

Thank you.