Im a little unsure as to what your after here.
Personally i auto tranfer anything downloaded to a folder on desktop i find it easy access. I find it hard to belive that downloaded movies are slowing ur comp down unless ur hd is full or nearing full. Go to start my computer and hover cursor over c drive to see how much space you have remaining. Concerning your drive cd rewriter/dvd combo is a drive that will only burn cds and play dvds, dvd +/_ rewriter will burn both. If your harddrive isnt full other problems your likely to have that are slowing you down is grayware or virus infection, go to http://housecall.trendmicro.com/ and treat ur pc to the full adware and virus scan. Delete all temp files offline content and cookies. Also ensure you only have programs running at start up that you require and that your toolbar isnt full up running programs u dont require. Also be sure your not running crack programs in your toolbar as they often conflict and slow you dramaticly and make sure you have all the relavant microsoft patches downloaded. Hope this helps.