Word document (doc, Docx format file) icon is displayed as a white square, because there is no default opening program. Here, WIN7 system is used to demonstrate the operation process of setting the default opening program for Docx format files:

First, open the Windows control panel of the computer system and click "Open Program".

2. After entering the program setting panel, click "Default Program".

3. Locate the item "Associate a file type or protocol with a program" and click Open.

4. Find two formats of "Doc and Docx" in the file type list, click one of them (the other setting method is the same), and click "Change Program" in the upper right corner.

5. Click and select "Word" in the recommended program list, and click "OK".

Six, as shown in the figure below, after setting the default program, the file saved by Word will display the file icon of Word.