Adding to what Broni stated, if C drive crashes, you will still have your programs.
The problem that arrises now is that the shortcut executables for those programs do not exist any more. They will not be on the desktop or in the program folder because you redid the C drive.
i'm gonna add a bit here....it's relatively common for a computer user with larger drives or multiple drives to break up the location of things...usually you'll have one partition/drive for windows, one for data, one for pictures, one for music, or however you want to separate things
and if you want....you CAN install programs to a different partition than the system partition (the one where windows is)...HOWEVER this USUALLY (depends on the program you're installing) only puts certain data files, setting files, etc.... on the second partition.. MOST programs (especially larger ones) REQUIRE a large portion of the actual program functionality to be on the system partition.....so you'll end up with some VERY important parts of the program residing on the C drive...not to mention all the registry entries in windows etc..
what this means is that if your C drive does die...you'll probably still retain the data files and settings for the programs that exist on the other drives...but the programs won't work (or might not work) once you install windows again because the registry entries won't exist and neither will most of the functional parts of the program
if you're installing the programs to a separate directory for the sake of saving space...this would help...if it's for the security of your programs in the event of a system partition failure.....it's not advised