I run my Razer mice without drivers, after setting up the profiles that I require, by disabling them from loading on startup.  It is possible to load the drivers manually by going into the Program Files\Razer\MouseName directory (by default) and running razerhid.exe.  However, there is no way to end them from within the driver interface - I would resort to opening task manager and killing and processes called razer*.exe.

I had suffered weird crashes before when fiddling with my mice like this, but I had never diagnosed the problem.  However, I can now confirm that with either the Lachesis and the BS:CE, if I kill the razer processes, then a short while later my PC will suddenly show a black screen, respond to no input and change the power button from it's usual "hold for 4 seconds to turn off" to "instant-off".  I have only tested these two mice, but it happens on both my home desktop PC (home built) and my Dell work laptop.

Has anyone else noticed this?