I have tried changing the TEMP folder of QGIS following this post,and although it wasnt required, I restarted the system after making the change, but still got no result (printscreen below). Is there an alternative way to change the location of the temporary folder for QGIS? Perhaps something about altering some installation files?
So, I found a solution as I was staring at my own printscreen. If you tick the box to use custom variables inside the options of QGIS it allows you to set new values to the QGIS variables such as the path to TEMP (see printscreen below). Anything written in the custom variables (1st highlighted box) can overwrite the current environmental variables (2nd highlighted box), as long as you set them to overwrite.