I try to do it now with the win32 api, but i cant get it to work. This is my code:

Code:
HANDLE hFloppy = CreateFile("\\\\.\\A:", GENERIC_ALL, 0, NULL, OPEN_EXISTING, FILE_SHARE_WRITE, NULL);
 WriteFile(hFloppy, bootBuf, 512, NULL, NULL);
 CloseHandle(hFloppy);