SSD is filling up...

Even when moving programs to install in Datapart C (D)  the 250 GB SSD C-OS partition is filling up rapidly.  Doesn't the Datapart C (D)share the load in any way?  Been trying to move files from old computer... 8100 to  8900 for two days.. cannot figure out how to get my software on the XPS 8900... do I just keep installing and when the SSC C-OS is full, will it then load over to the Datapart C (D).

Do a lot of video and audio editing and have big programs... Premiere, After Affects, Audition, RX5, etc. and not enough room to install them!  Newbie at this SSD thing... can someone help me out?  Thanks much.