Blue Screens usually point towards more general issues with the system that are independent of KeyShot.
Possible causes fro Blue Screens can be plenty, reaching from driver issues over to aggressive over-clocks or overheating issues to Hardware issues.
The load KeyShot can put on the CPU is fairly unique and may not be comparable to the load the other systems experience.
Please try to set KeyShot and the rendering slave to only use half the cores or less. If that improves the stability please check the system Temperatures since there might be an overheating issue.
A system like the one you describe can output a lot of heat when under full load.
Checking for Driver issues:
- The simplest thing to do is to update the graphics-card driver.
- If that does not resolve the issues try unplugging or swapping all peripheral devices.
If you can narrow it down to one specific device try updating its driver.
If none of the above seems to improve the system stability i suggest to run a load test on the system.