I, too, was getting the error message “No disk in drive. Please insert a writable CD in Drive x:” using WINXP and a LG GSA_4163B dual layer DVD/CD burner. This was happening with various disc makes.
After opening Nero and burning one test file to a RW disc, I was able to burn directly to a blank disc with WINXP with Nero both open and closed. This made me think that the ‘burning pathway’ was not automatically assigned to WINXP but was accessable once Nero had ‘activated’ it.
If you do have trouble adding extra files to the disc with WINXP after the initial burn, additional files CAN be burnt with Nero in ‘continue multisession’ mode. (As Nero is open why not use it for burning?)
After rebooting the PC I still had to open Nero to initialise WINXP burning. But I was able to then burn to various discs with nero closed.
Once a disc has been burnt by WINXP or Nero it will be recognised as burnable by Windows and the normal Windows option panels pop up.
Don’t ask me why but it works!