[dogma1138]

It's actually not bashrc that is the direct culprit but a few issues with how Cygwin emulates posix.

Best solution is to edit /etc/bash_completion.d and remove anything you don't need this can shave off 2-3 seconds of the load time.

Since windows now should have a native fork() call Cygwin might be updated on its own which will make it about as fast as a native nix system, that said Cygwin will need to make a dedicated version for windows 10 for this to work.