Anyway for those who dosen't have much space on ur c: drive, these are somethings u can do.

1. Clear ur windows restore points, jus keep the most recent one (Just be v-sure before u do something like that). I saved abt 600meg

2. Move ur windows update files, they are usually store in ur c:\windows and are named $NT.... . If u can't find them, they might be hidden go to 'Tools"->"Folder options" and then "view", Sekect show hidden files and directory. Delete them if u are quite sure u wont roll back the updates or just shift them to some where else, when u need them just copy back to ur windows directory.