Hey there shadath. What OS are you using? Have you checked the Downloads folder for older downloads? This is the default path for download, it is located on you C: drive in your User Folder? You could also try cleaning up your temporary files as well. Take a look at this article here: http://www.howtogeek.com/125923/7-ways-to-free-up-hard-disk-space-on-windows/ it has tips on how to do the things I've mentioned and a few other ways to free up space on you C: drive.
Hope that helps.
Boogieman_WD