When you paste text from a Microsoft Word document onto a web page, it usually includes a lot of non-standard HTML code. This code doesn't work well in all the browsers and it makes it more difficult to edit the HTML code in your page. Many advanced web page editors, such as Adobe Dreamweaver, have the ability to clean up the Word HTML code. Moodle's web page editor can also clean up Word HTML code.
When pasting text that was copied from Word, use the Paste from Word icon. This will strip out most of Word's non-standard HTML code: