In my jobs almost two decades ago, IT experts would keep the size of Windows' main partition (C drive) extremely small compared to the other partitions. They would argued this runs PC at optimum speed without slowing down.
But the downside of it is, C: drive easily fills up if kept small, and soon you can't install new software as it runs out of space. Even if I install software in D: drive, part of it is always copied to C: which fills it up.
My question is this practice still good? Why it is done. What are its main advantage if any? One obvious one is if primary partition crashes, your data is safe in secondary.
The reason I am asking this question is because I am trying to update Visual Studio and I can't because I have only 24MB left in primary partition.