Things like installing steam games to another hard drive are one thing, installing actual programs that you want to run on another drive is another. I dont think your going to be able to install other programs to your hdd, they are going to default to the main drive unless they give you an option to install somewhere else. Your best bet would be to get a bigger ssd. Also if its just things like the temp files and cache from the programs causing the issue run something like Ccleaner to clean those folders out and free up space.