Word 2003 and 2007 are the most common versions on the market
Microsoft has failed in its attempt to dismiss a court case that would stop it selling Word.
The software giant appealed against a ruling which found it infringed a patent owned by Canadian company i4i.
With the failure of the appeal Microsoft must now pay i4i damages of $290m (£182m) and comply with an injunction ending the sales of some versions of Word.
The injunction is scheduled to go into effect on 11 January.
Microsoft said the ban would prohibit the sale of all available versions of Microsoft Word and Microsoft Office software from the date that the injunction comes into force.
Versions of the software sold before that date, including Word 2003 and Word 2007, will not be hit by the ruling.
"We have been preparing for this possibility since the District Court issued its injunction in August 2009 and have put the wheels in motion to remove this little-used feature from these products," Microsoft said.
"Therefore, we expect to have copies of Microsoft Word 2007 and Office 2007, with this feature removed, available for US sale and distribution by the injunction date," it said.
"Beta versions of Microsoft Word 2010 and Microsoft Office 2010, which are available now for downloading, do not contain the technology covered by the injunction," Microsoft added.
Microsoft was accused by i4i of infringing on a 1998 XML patent in its Word 2003 and Word 2007 programs.
Word uses XML, or the Extensible Markup Language, to open .XML, .DOCX, and .DOCM files.
The initial ruling in the court dispute between i4i and Microsoft was made in August. At that time Microsoft was found to have infringed the i4i patent and the Canadian firm was awarded damages.
The injunction on sales was imposed at the same time but a Microsoft appeal initially overturned that ban on US sales. The stay on the injunction has now run out and, as a result, Microsoft must stop selling infringing versions of Word.
Microsoft said it might file further appeals, but that it was keen to comply with the injunction.
"While we are moving quickly to address the injunction issue, we are also considering our legal options," it said.