I always keep my recycle bin clean and i do not have Norton. I started rendering a video this afternoon “after setting” options-preferences-video-Dynamic Ram Preview Max MB to “0” I did regain 6 gigs of hard drive space after that change but when rendering started you can watch the disk space on my C drive eat up and down to windows “low disk space warning” Rendering was at 90% so i hurriedly deleted any of my old large files i could find.When rendering got to 100% a error message said rendering failed.I did recover all my disk space back after i closed Vegas Pro program though.So it still remains a mystery why its eating so much disk space