If the crashes are somewhat random then its not due to location of installation and more likely a hardware failure of some kind. If always crashing in the same spot it may be an issue where an object ( file ) is unavailable and give an error message usually, although sometimes it can black screen and then crash back out to the desktop.
I would wipe both drives clean and install games and software to the C: drive and store your music etc on your D: drive ( 2nd hdd ), this way any games that were designed with predetermined mappings to expect data to reside on C: will not have any issues if there is a path issue is installed to any other letter other than C:
Splitting your data up in this manner also allows for future rebuilds without fear for lost data.
Problems can also occur if say you installed a game to D:, then rebuilt drive C: with a clean os, and try to associate the games on D: with the OS at C:, in which registry settings mismatch to support the game and games wont run or will run with issues or they have registry requirements.