BSOD's can be the sympton for a variety of causes.
Try some generic trouble shooting first such as running a full disk check to see if it can fix faulted registry entries or find errors with the disk surface.
Easiest way to do so is going into windows, right click your C:\ drive (Presuming this is where Windows is installed onto (Forget about the other drives at the moment)
Once right clicked selectc Properties>>Tools>>and under disk cheking select check now.
Mark both the option boxes to fully scan the disk and apply + reboot PC.
Let it run it's think (Might take some time, 15-30 minutes, so go have a coffee)
See if that fixes the issues.
As for registry programs such as RegistryDoctor or CCleaner. My advice is not to use programs such as those unless you keep a backup of older registries and are able to reload the previous registry entries back to Windows registry when things start to fail.
Anyhow, try the disk check. If you can't get into Windows then try starting up Windows if not there are other ways to get it started