i would also like to know whether an external dvd burner i buy has to be usb2.0, 1.1, or firewire im new to all this so iwould like some advice please my computer is a compaq presario s5100uk.
USB 1.1 is too slow for a DVD writer.
You need either USB 2.0 (HiSpeed) or Firewire. USB 2.0 drives are common, external drives with Firewire are rare and expensive - mostly you’ll need to buy enclosure and internal drive separately and build your own unit.
In case your laptop does not have an USB 2.0 interface, you can also add a Cardbus (PCMCIA) controller card. Make sure it has Nec chipset then.