Not enough memory

For some reason, I just did a factory restore on my laptop, and I dont know why...but when I first got the laptop it said I had something like..180MB? of free space, but now it says I only have 50MB of free space...I did the factory restore, and only downloaded one game that only takes up 20MB of space, but my laptop tell me that I have used all of my free space. and I havnt done anything, also when I go to defrag, as im sitting there, the space is going down, im not doing anything at all, and % by % it goes down..little by little, and I deleted TONS of stuff on my laptop (stuff that came with the laptop, photoshop, dell games, etc) and the space keeps going down, how do I fix this?