Changing D Drive Backup To Manual??

Any help that can be offered is much appreciated!  I started getting the "Drive D is full" message a few days ago.  Then I found out that it automatically comes as being the back up drive.  I deleted the file that needed to be deleted to relieve the space.  I'm working on getting an external drive to use for back up files. 

What I need to know now, and can't seem to find anywhere, is how to change the D Drive to back up as manual so I don't have to do this every single time.  AND, If I do that, is it going to stop using the D Drive as a system restore point automatically?  Because if it is, I'll just do it every single time... better than forcing me to go in and do the system restore points manually. 

Anyone who can offer any information would be much appreciated!!  Thank you!!  :emotion-2: