VOID
RtlZeroMemory(
IN PVOID Destination,
IN ULONG Length
);
RtlZeroMemory fills a block of memory with zeros, given a pointer to the block and the length, in bytes, to be filled.
Callers of RtlZeroMemory can be running at any IRQL if the Destination block is in nonpaged pool. Otherwise, the caller must be running at IRQL < DISPATCH_LEVEL.