Some things beyound my understanding. Here is a story. After a windows update on our DELL server, windows 2003 refused to boot, even in the safe mode. We decided to run the recovery from the installation DVD. But the problem instantly occured - the installer did not recognize the DELL's PERC/5i RAID controller. The machine did not have a floppy drive (even though the motherboard actually has a floppy connector on it). We contacted the DELL tech support and were told to put the PERC driver to a USB flash drive using special utility available also to download (the content of the drive was gone, so saddly to say). Then, standard F6 key worked and the installer saw the driver on the USB drive as it was a floppy disk.
How it did that? No clue.