Final answer:
The error message suggests incompatible file type and a possible solution is to change the file association or convert the file to the correct format.
Step-by-step explanation:
The error message 'when filing, the document opens up in Windows Photo Viewer or an external viewer' suggests that the file type being used is not compatible with the program you are trying to open it with. For example, if you are trying to open a PDF document but it opens in a photo viewer, it indicates that the file association is incorrect.
A possible solution is to change the file association so that the document opens in the correct program. To do this, right-click on the file, select 'Open with', and choose the appropriate program. You can also set the default program for opening specific file types in the Windows settings.
Another solution is to convert the file to the correct format. For example, if you have a document saved as an image file, you can use an online converter or specialized software to convert it to a PDF or Word document.