I had an issue where my 120GB SSD drive was getting quite full, and I could not work out why. It basically has my OS, and programmes on it, and no user data (as such) is stored on the SSD, but rather on my 1tb internal HDD instead.
After some googling I came across this nifty bit of software : WinDirStat which is free to download and it does a directory (folder) tree search of your chosen drives and shows you where the space is being taken up.
I ran it and found 37gb of video files on my SSD, using WinDirStat I followed the path to discover that Nero (even though i had told it NOT to retain a copy) had stored copies of video files I had copied to disks. Even though the original video files were on my 1TB HDD, Nero had made copies on the SSD as well, so using WinDirStat, I deleted those folders and suddenly my free space returned to where I thought it should have been
So thought I would share this wonderful little program with everyone here on AP. Cannot recommend it highly enough.