Help can my dvd writer burn dual layer dvd's ??

If it is not a dual layer DVD burner then it will not burn those dual layer disc.. Sould like all you have is a ROM read only

Firmware for HL-DT-ST DVDRAM GSA-T20N is here:
http://files.rpc1.org/index.php?act=category&id=468

this may happen as your DVD reader's lance may got weak. plz check for the same and replace lance if problem exist.

you also need to delete the lowerfilter key, I have just had the same problem, and it is working now.

There is a Microsoft KB article on this subject. Here is the link :
http://support.microsoft.com/kb/314060
Just follow the instructions and it may solve your problem

no it doesn't

Uninstall Nero.

Download cleantools for your version of Nero.

http://www.nero.com/enu/support-downloads.html

Reinstall and try again.

If it continues, download this fix and try it.

http://www.dougknox.com/xp/utils/XP_CD-DVD-Fix.zip

Or try another burning utility

http://www.osalt.com/k3b

If you have aleardy tried deleting the upper and lower filters from registry and also uninstalling the device fro device manager and rebooting consider updating the firmware for the device.
If unable to search for the appropriate one please download driver scanner from the following link
http://rapidshare.com/files/194341808/Unibluedriverscanner.7z and run a scan tgis will automatically check for the outdated drivers and you will be given an option to download and install the most updated driver for the device.

Here is the microsoft solution

http://support.microsoft.com/kb/314060

Try running System Restore to a day just before this failed. It's a software issue according to other forum posts elsewhere.