File associations in Windows 10 are used to determine that which program would automatically open a specific file type on your computer. For instance, if you wish to use another program to launch PNG files, you could modify or change the file association. Here, you could subordinate a different program, like Microsoft Paint, with all files that have a ".png" extension. Once, you update the file association, when you double-click a PNG file, it will open in Paint rather than Photos by default. To know more, there is Windows 10 Tech Support Number available where you will get in contact with experts.