As we know, we can’t open a file which extension is .docx in Microsoft Word 2003. The .docx is Microsoft Word 2007 file. If your PC have installed Microsoft Word 2003 an you don’t want install Microsoft Office 2007 especially Microsoft Word 2007, it’s impossible to open that file (.docx). So How to solve this problem?. Don’t worry, it’s easy to solve this. The Steps are :