cowtest.c

#include <windows.h>
#include <stdio.h>

static int data[1] __attribute__((aligned(4096))) = {1};

int main()
{
        MEMORY_BASIC_INFORMATION info;
        VirtualQuery(&data, &info, sizeof(info));
        printf("%d\n", info.Protect==PAGE_WRITECOPY);
        DWORD old, old2;
        VirtualProtect(&data, 4096, PAGE_NOACCESS, &old); // ANY flag for that matter
        VirtualProtect(&data, 4096, old, &old);
        printf("%d\n", info.Protect==PAGE_WRITECOPY);
}