Office documents open in IE browser instead of their own programs

This behavior may occur if Internet Explorer is configured to host documents for Office programs that are installed on the computer. By default, Internet Explorer is configured to host documents for Office programs. If you want to change this behavior, do the following.

Make IE open linked Office documents in the Office program itself

If you find this happening on your Windows 10 PC, create a system restore point first, and try the following. Download FileTypesMan from Nirsoft. Run this portable too and select the file extension whose behavior you want to change. In this image, I have selected .docx files. Double-click on it to open the EDit File Type box. Here make sure that the Don’t open inside a web browser box is checked. Click OK and exit. This will disable the browser integration, the the Office document will open in the respective Office program itself and not the Internet Explorer browser.

Windows 8.1, Windows 7 and Windows Vista users can either use the above-metioned FileTypesMan tool or they can visit KB162059 and click on the blue download button. This download, when run, will fix your problem automatically for you.