If, as your first post seems to suggest, the page # is in a textbox or frame, all you really need to do is click on the border of the frame of the object holding the page #, then press 'Delete'.

That said, the issue has nothing to do with compatibility between Word 2003 and Word 2010; just a lack of understanding about the different ways features such as page numbers might be inserted. The "Remove Page Numbers" function only works with page #s inserted via the "Insert Page Numbers" function during current editing session for the document; close & re-open it and Word won't remember that it's been inserted and, so, can't remove it that way.

As for Office 2016, you're better off staying with Office 2010 (IMHO) unless Office 2016 provides some added functionality you really need.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

I'm not seeing "Delete" only "Cut", and it is grayed-out and non-functional.

BTW, I tried using section breaks rather than my original page breaks, and it achieved nothing, and since this document is time-sensitive, I'm running of time...I may just save as text, paste into a fresh .docx document and spend a few hours formatting it using the original as a guide...very frustrating for someone who is not a Word expert, and wish the application offered a "dummies" mode...99% of features I will never use, like for legal and scientific uses, just to cite a couple.

I appreciate the tip to stay with 2010 rather than going to Office 2016...I had read that 2016 would be needed for 64-bit Windows 10, but didn't save the link, and it might have been mis-information. I'll try the 2010 version first when the new machine arrives.

Click on a frame, shape or textbox border. You will get sizing squares on the corners when you do this. To delete a selected frame, shape or textbox, press the delete key.

Manual page breaks are the bane of editors. Section breaks instead compounds the problem. Section breaks contain a lot of formatting.

That may work best. If possible, use styles for the formatting. Use page-break-before formatting for headings that you want to start a new page.

You may want to look into WordPad which comes with Windows and has none of those features.

I use Word 2010 (32-bit) on Office 10 (64-bit).