How do I fill in a Word document received by email?

I have received a form by email that has to be filled in and either printed or sent back by email. When I type, the characters move everything to the right like when you use the space key. Can't figure out why this is. What do I do to stop everything moving like that whenI type?

By the way, this is a Microsoft Word 97-2003 document

2 Answers

Press Insert to replace the existing text instead of moving it away.

Otherwise, print the document, fill it out by hand and scan it.

The form was created with tab stops, go to menu bar, format then tabs from the tab pop-up window click clear all