Did you add a Filename field to the header? In that case, you can update the field by switching to Print Preview and then exit (you can use Ctrl+P followed by ESC).

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Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional

Thank you Stefan,
I did add the filename to the header.
My question is how can I auto update it after each change of doc's name.
That's to much work to open about 1000 files and in each one of them to press ctrl+p etc..
I just want to copy and save each file by a different name ,so the header shall get the new name as well.

Hope I'm being clear.

Cheers.

Unfortunately, FILENAME fields do not update automatically. You'll need a macro to do the job for you, for example, when a document is opened.

__________________
Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional