See a graph of directory allocation. It can also show you which files have the most recent access dates. Use drag-and-drop to move files or to delete them, letting DiskFrontier track all the changes you make.
Its an excellent freeware tool. Only about 266KB in size..
Download here
The Windows built in Add/remove program tool shows you the list of all programs installed, including the space occupied by each of them.
In case you havent noticed, its in Control Panel..