Hi Rich,
this kind of crashes often points to hardware issues, starting with overheating (narrow case, stopped cooler fans, dusty coolers), bad mounted components and ending with memory, mainboard or disk failure ...
Start looking in the event log would be the first step, opening the case and perform optical checking another one.
The error booting from WHS DVD often happened with certain DVD drives or these drives connected to an SATA port higher than the first 4.
Best greetings from Germany
Olaf