It is worth noting that for recent versions, Cubase shows where exactly the program crashed in the Safe Mode startup dialog the next time you start Cubase, right at the top where it says “The application was terminated with an error while executing the following file”. If the following line e.g. shows a path to a VST plugin, the crash was caused by that plugin and you need to update it or check with the vendor.
See this example from another thread here:
So for most cases, it is actually not necessary to install WinDbg anymore.