well you can try a double for loop to copy the data. for(int i=0; i<47; i++) for(int j=0; j<20; j++) old[i][j] = new[i][j]; i wouldn't recomend that (memcpy should work) but at least you can get your debugger going again to examine the memory. if it still crashes then you have some other problem =/

are you sure you're including string.h in the file that uses memcpy? that error you're getting means it can't find the memcpy function at all.