Hello- please start Rhino in Safe Mode (there is an icon for this in the Rhinoceros program group) and assuming that opens, open Options > Plug-ins and filter the view for ‘Plug-ins that do not ship with Rhino’ Disable these and then restart Rhino normally. If it starts, enable one plug-in at a time and restart, and see if you can tell which one is causing the crash.
-Pascal