__setReg
Microsoft Specific
Sets the value of a register specified by the first parameter, which are the same values as declared in the header file intrin.h.
void __setReg( int Register, unsigned __int64 Value );
Attempting to write directly to processor registers can produce unexpected results. Some registers are not writeable in user mode and might throw a hardware exception or ignore attempts to write to them. For more information, see the processor documentation.
This routine is only available as an intrinsic.