Fix the header on WP website (Windows server)

Hello, Our WP website is on a Windows server. An error happened and website header got messed up. It is listing all the pages on our blog, in the header, instead showing only the pages selected to be included in the header. Projected will be awarded to a person who is expert in WP and windows server. Selected person will be expected to fix the header back to the state where it lists only the pages that we provide him to be listed in the header, and restore the check and uncheck option on " Include this page in lists of pages" function, as this function is not working as well. The error is that even if you uncheck this option, the software automatically restores it back to checked status and page remains listed in the header, even though you want to remove that page from header. The selected person after getting the project will get from us the list of pages to be included in the header, leave those pages in the header and remove all the others from the header. Thank you.