1) Set DVDRW to Master and ROM to Slave.
2) Make sure you set the "jumpers" on the back of the units to reflext this.
3) Make sure IDE and power leads are connected properly too both and also that the IDE cables are attached properly to the mobo.
4) Make sure that in the BIOS these are set to "Auto-detect".
5) Try un-installing the IDE Channel upon which these 2 units are connected and then reboot, this will re-install it again.
6) If the BIOS is set to "Auto-detect" Windows XP will automatically detect them.
7) The drivers required for the DVDRW are already contained as part of Windows XP.
8) Make sure IMAPI CD-Burning COM Service is "Disabled" in Control Panel->Administrative Tools->Services.
Above all "Don't Panic", you will soon get it sorted!!