you still have 66 gb to spare which is a lot,...
you can point new installations to a folder on another harddrive (it will then install minimal files and registry entries on the c partition). All images, video, music and etc can easily be moved to another harddrive without issues,.. if you have a lot in the documents folder like someone mentioned,... I would just cut and paste the non essential stuff over to a new folder on another harddrive,... no need to move the folder itself and all that,...
I mean it really is a simple thing of creating folders like these on the root of the third drive and cut and paste
music
video
pictures
drivers
Now if you have 3000 programs installed,.. next time you install one create a folder on another harddrive "games" for instance and then instead of pointing to c:\windows\program files\,..... point it to e:\games\,...
Just some thoughts,.. and a lot easier\more reliable than spanning drives and such.