Programs don't usually take up the most space on a PC, it's usually the data that uses the most space. It is probably pictures, videos, and things like that taking up most of the space. There is a great program for determining what files are taking up the space on your HD, it's called WinDirStat. I'll post a link to it below.
Try deleting some duplicate images, files on your drive
I would suggest you use DuplicateFilesDeleter program, Its simple, multi-threaded & effective tool that ensures 100% accuracy. You can then choose to delete the selected duplicate or original files. Check this out for sure to find resolution to most of the duplicate filess/image issues !!!