Reprinted from: https://jingyan.baidu.com/article/1974b28985d4bbf4b0f77458.html
The reproduced content is as follows:
After installing Office (2010 or 2013, etc.), many friends found that there are no Word, Excel, PowerPoint and other items in the right-click New, but their Office is clearly installed. What should I do at this time? Here, this article provides you with a simple solution.
1. Click Start, find the Run command line, enter regedit, and open the registry.
2. Find the HKEY_CLASSES_ROOT directory on the left and expand it.
3. First, we use the CTRL + F shortcut to find the location of "docx", of course, you can also pull down to find it yourself. 
4. After finding it, do not expand the directory. We can see that there is one on the right (default), the default value at this time is Word_auto_file, it does not matter if it is not the value.
5. Double-click (default) an item and change it to Word.Document.12.
6. Close the registry and refresh the desktop. This is the magical return of Word we found in the right-click to create a new one.
7. Add the 2003 version of word in the right button. Open the registry, find HKEY_CLASSES_ROOT\.doc\Word.Document.8\ShellNew, create a new string value, the name is "FileName", and the string value is "word.doc". 
Close the registry, refresh the desktop, right-click - New, you can see the option of "New Microsoft Office Word 97 - 2003 Document".
Note: Sometimes the desktop needs to be refreshed several times to see it. I came out after refreshing it twice.
8. In the same way, we enter the registry to find the location of "xlsx" and change (default) to Excel.Sheet.12; then look for "pptx" and change (default) to PowerPoint.Show.12.
Close the registry, return to the desktop, and after multiple refreshes, right-click the newly created Word, Excel, and PPT, all of them are back.