 In this video I'm going to show how to change the temporary folder where QGIS stores temporary files. By default QGIS will take the folder indicated in the environment variables of your system. But this can be overruled. You go to settings, options and there you see the system tab. You scroll down and here you can find all the variables. And here you can see which temp variables are used, TEMP and TMP. And how they are linked to folders taken from your system settings. You can overrule this by checking the box, use custom variables. You need to restart after setting them. To add a new one I choose overwrite. I type exactly the name of the temp variable here and I give it a new value. So maybe I want to save it to another drive, to the temp folder. And I do the same for the TMP variable. I click OK and after a restart that will be applied.