Use Emule or Limewire (Use Google) to download a working copy of "UltraISO". Then use UltraISO to create an ISO image of your CD/DVD Map Disk onto your HDD. Use Alcohol 120% to burn the HDD image onto a CD-R or DVD+R at the slowest speed possible to you. I would suggest you use a RW disk until you get a working copy!
You cannot just extract the files as the BMW Nav Computer will NOT recognise a Windows bootable disk. UltraISO produces an exact replica of your Map Disk..... I have copied over 40 Map DVD's & can assure you that this works.