What is the default extension for a document created in word?
That depends on the version of Word you're using. The older applications' (Word 97-2003) default extension was .doc; the newer extension (Word 2007 and later) is .docx because Word now uses open source xml tags.If you are sharing files with someone using an older version of Word, use the .doc or .rtf (rich text format) file format. If you are sharing files with someone using different word processing software, save a copy of your document in .rtf format.