Look in the Device Manager .........

Start | Control Panel | System in classic view | Hardware tab | Device Manager

Click on the (+) next to DVD/CD-ROM drives.  This will reveal the Brand and Model of
drive.  Please post that.

Also, please tell us the model of your computer.

My computer model is Dimension 3000.

CD-Rom is HL-DT-ST-CD-RW GCE-8483B.

DVD is Hitachi DVD ROM GD-2500

Hope this helps.

Only the HL-DT-ST CDRW GCE-8483B drive is a writing drive.

What happens when you try to write to a CDR with the CDRW drive?
Do you get an error message? 
What brand and type of discs are you using to write to? 
What burning software are you using?

Error tells me that I don't have a writeable disc in the drive.

I use GQ CD-R and Memorex CD-RW.

Have you ever written to the media you list?
Have you tried higher quality media. 

If yes to above, try this Firmware here ..........

http://support.dell.com/support/downloads/download.aspx?c=us&cs=19&l=en&s=dhs&releaseid=R100582&SystemID=DIM_CEL_3000&servicetag=&os=WW1&osl=en&deviceid=5891&devlib=0&typecnt=0&vercnt=1&catid=-1&impid=-1&formatcnt=1&libid=32&fileid=130199

I haven't written to any media as yet...who do you suggest?

I downloaded your fix and it wouldn't complete, Mismatch between device and protocol.

The media you listed is of low quality.  Memorex CDRW is usually
troublesome and the other CDR is an off-brand.  Try a know major
brand of media (small quanitity) to test the drive.  Good know
brands are Verbatum, TDK, Maxell, Sony, etc.