Device Filter Utility
Download Devfilter.exe
This utility will easily allow you to see what filter drivers are being used for your CD/DVD writers. It is provided for free by Bustrace.
A common problem with CD/DVD writing is that it goes around the OS to talk with the hardware since Microsoft hasn't really provided much support for writing optical disks yet. This means that sometimes other writing programs (which are part of lots of other software these days) can get installed in an order that intercepts and interferes with commands or messages destined for the write engines that HP uses and causes application/drive communication problems.
Above is a screenshot of the Devfilter application. When you highlight the DVD drive in your dc3000 or dc4000 (in this case an HP DVD Writer 420n USB Device), you'll see which filters are installed and which order the commands/messages flow through the filters. The software that comes with the dc3000/dc4000 puts in three filters, PFC, drvmcdb, and PxHelp20. If you highlight them, you can see that they are from Sonic (for RecordNow) and Padus (for Showbiz). When you see other filters, check to see which companies have installed them and if they are from Ahead, or Roxio (Adaptec), and you're experiencing writing problems, you should uninstall software from those application (i.e., Nero or EasyCD/DVD Creator). You can use this devfilter utility to make sure that the filters are getting removed when you remove the associated application. It's best to avoid installing multiple CD/DVD recording software packages on a PC or else you're likely to run into interaction problems that cause write failures or other problems while attempting to write disks.
If you are having serious problems with the filter drivers to the point where your CD/DVD drives disappear completely, you can follow these instructions to remove the filters completely and then reinstall the CD/DVD writing application again.