Is there way to use RAM instead of disk?

I cant process long audio tracks because my hard disk has only 4 GB of free space left and since I already have deleted everything I can delete there’s no such option anymore as to empty temp dir, but I do have 8 GB or ram of which 6GB is free, which would be enough. Is there way to tell Audacity to use RAM instead of disk so that I could finish my processing?

You could create a RAM disk, but I wouldn’t recommend it. 4 GB free disk space is way too low and your computer is at risk of crashing at any moment. On Windows it is generally recommended to have at least 10% free disk space at all times so that Windows can perform its background tasks. You should free up some disk space.

Or you could move your data to a couple of different online servers, or buy an external hard drive.