Hello Linda,
Thank you for posting your query in Microsoft Office Community.
Before we proceed, I need more information to help you better.
1) Does this issue occur only when you try opening *.rtf file?
2) Are you able to open *.doc or *.docx extension document?
Let's try the following methods and verify the result.
1) Open Word and then try opening the *.rtf file and verify the result.
2) If issue still persists, repair the Office suite following instructions in the article below, then try opening the *.rtf file and check if it opens.
http://office.microsoft.com/en-us/powerpoint-help/repair-office-programs-HA010357402.aspx
Hope the above information helps. Reply with necessary information and the result to help you further.
Thank you.
