Can we please let some air out of this balloon before it bursts?
This is not preschool.
OPs Problem: CloneBD taking the whole system down - that would have been possible back in the good ol' Windows 95 times.
But with the current Windows design, there are only ('by design') two possiblilties (and an unlikely third):
- bad hardware component (this sort of includes overclocking, since that renders the CPU bad under the circumstances)
- bug in some driver
- the unlikely third: virus with rootkit (which is sort of the same thing as "bug in some driver")
A user mode application can crash, but simply cannot take down the system.
CloneBD does use a driver (elbycdio.sys from Elby as well), but that thing has been around for so many years, I'd rule it out as a "buggy driver".
CloneBD tries to utilize the whole CPU power (meaning: 100% usage, ideally sees to it, that all cores are fully loaded). Has to do that, of course, because you want your results as fast as doable.
Flaws in the PC hardware - heatwise - will show up that way.
Since most applications, like word processors, internet browsers and such let the CPU doze off bored (doesn't do anything but wait for your keystrokes, then goes back to bed), such things will not pop up just like that.
So it's possible, that heating up the CPU (and with that some components surrounding it) will cause your PC to fail.
If you want to rule that out, maybe run a tool like this one:
http://www.jam-software.com/heavyload/?language=EN
for a few hours (over night) and if it survives 100% CPU load without crashing, then that's probably not the cause.
System crashes usually come with a minidump.
See control panel - system - advanced - recovery for settings controlling if and where they are stored.
There you can also specify that the system should display a bluescreen instead of just rebooting. That thing is annoying, but doesn't leave you in the dark as much as a plain reboot without explanation.
Check if a minidump file has been created in that given location (usually c:\windows\minidump). If it was a failing driver, a minidump will - in maybe 50% of the cases - reveal that (unfortunately no more than that, if at all, it's a bit of a crystal ball thing, because a misbehaving driver can make other drivers look like the cause, even if innocent).