Should not of stopped it. My pc would not start until i did a system restore. But now using windows defrag its taking ages and taking my space again. It went up to 52gb and then starts going down in 100 mb like 52gb then 51.9...51.8 etc.
I'm not an expert on defragging, but in theory wouldn't it use up space as it's moving files from one to play to another, stores them, then puts them in the appropriate location later once it finds more files like it?