In order to solve the issue, navigate to Control Panel > Programs > Default Programs > Set Default Programs, select Photoshop from the list and click Choose defaults for this program. Un-check the extensions you don't want to open with Photoshop, click Save and restart your computer.
Alternatively, right-click on the file you want to open, move your mouse over Open with and press Choose default program. Select the application you usually use to open the file, check the Always use the selected program to open this kind of files box and click OK.