Dynamic Memory Allocation in fast RAM

On a Windows 32-bit and 64-bit machine, I have to allocate memory to store large amounts of data that are streaming live, a total of around 1GB. If I use malloc(), I am going to obtain a virtual memory address, and this address could be actually causing some paging to the hard drive depending on the amount of memory I have. Unfortunately I'm afraid that the HD will impact performance and cause data to be missing.

Is there a way to force memory to allocate only in RAM, even if it means that I get an error when not enough memory is available (so the user needs to close other things or use another machine)? I want to guarantee that all operations will be done in memory. If this fails, forcing the application to exit is acceptable.

I know that another process may come in and itself take some memory, but I am not worried because in this machine that is not happening (it'll be the only application on the machine to be doing this large allocation).

[Edit:] My attempt so far has been to try use VirtualLock as follows:

if(!SetProcessWorkingSetSize(this, 300000, 300008))
    printf("Error Changing Working Set Size\n");

// Allocate 1GB space
unsigned long sz = sizeof(unsigned char)*1000000000;
unsigned char * m_buffer = (unsigned char *) malloc(sz);

if(m_buffer == NULL)
{
    printf("Memory Allocation failed\n");
}
else
{
    // Protect memory from being swapped
    if(!VirtualLock(m_buffer , sz))
    {
           printf("Memory swap protection failed\n");
    }           
}

But the change in Working set fails, and so does the VirtualLock. Malloc does return non-null.

[Edit2] I have tried also:

 unsigned long sz = sizeof(unsigned char)*1000000000;
 LPVOID lpvResult;
 lpvResult = VirtualAlloc(NULL,sz, MEM_PHYSICAL|MEM_RESERVE, PAGE_NOCACHE);

But lpvResult is 0, so no luck there either.