It was recently discovered that the WIBU key driver was causing random crashes on some Windows 8 systems. If you are experiencing this problem, the solution is to first uinstall the WIBU Key in Add/Remove programs, then reinstall it using the new installer downloaded from the following link:
https://app.box.com/s/rkq0kj272xtyxzqzcw3f
There is also the possibility that the crashing problem is not specific to Windows 8 but rather some other system conflict, so if you are having a problem with crashes on any version of Windows the first thing to try is updating the WIBU Key driver using the file above, which will work for any version of Windows-- both 32 bit and 64 bit.
Note that uninstalling showsim does not uninstall the WIBU key driver, it must be uninstalled seperately. There is no need to reinstall ShowSim for fixing this problem, the WIBU key driver is a seperate entity.