I put some add-on a/c manual files on a CD-ROM to print them somewhewre else and now that the job is done, I cannot delete the files from the CD-ROM. Windows XP Home Ed tells me that such files cannot be deleted (big white cross in red circle stuff and serious string music announcing this). I just surfed to the MS website and they say that you cannot delete files on a CD-ROM by design (yeah, by design). I can add files or folders, and I can over-write them too -- but I can never delete them from the CD-ROM. Is this nuts or what?JS

I was under the impression that if it was not a CD rewritable media (CD-RW), that once it was burned, that was it.ROM = Read Only Memory Regards, MichaelKDFWhttp://www.calvirair.com/mcpics/PBTMCa.jpgCalVirAir International VACalVirAir International

Being able to delete files from a CD-ROM has zero to do with Microsoft and more to do with the features of your burning software and what pieces you installed.On my office system, my Adaptec burning software contains an applet which allows you to treat your CD/RW's like little hard drives--but the catch is the applet must be loaded in the background for the CD/RW to work this way and it must be loaded on any system that reads the CD.Only other way you can delete the files is to erase the CD, or overwrite the files with the null files of the same name although this may not work depending on how you lay out your recording sessions.-John

>I put some add-on a/c manual files on a CD-ROM to print them>somewhewre else and now that the job is done, I cannot delete>the files from the CD-ROM. Windows XP Home Ed tells me that>such files cannot be deleted (big white cross in red circle>stuff and serious string music announcing this). >>I just surfed to the MS website and they say that you cannot>delete files on a CD-ROM by design (yeah, by design). I can>add files or folders, and I can over-write them too -- but I>can never delete them from the CD-ROM. >>Is this nuts or what?It's not nuts at all. Time for a little CDROM 101:There are 2 types of writable CD media. There's CDR, and there's CDRW.Let's talk first about CDR media, which is what I believe you are using. Data burned onto a CDR can not be "removed". Once it's written, there's no changing it. A laser is physically "burning" the bits on to the CDR, and once they've been burned, they can't be changed. You mentioned being able to add files and overwrite files to your CD. Well you are not actually overwriting the files on a CDR, even though that's what it appears to look like. Let me explain. Whenever you write data to a CD, you are also creating a special invisible "table of contents" on the CD. This table of contents is called the "file allocation table". The data in the table tells the computer reading the disc about the "current" files available on the CD. It contains information about each file so that the computer will know where the files reside on the CD. (Think sectors, tracks, and blocks). As you have said, you are able to add new files and directories to a CDR and even "overwrite" files that are already on the CDR, but you can not delete them. First of all, you are not actually overwriting any files on a CDR. What you are really doing is adding a new version of that file to the CDR. The old version is actually still there -- we can't change the bits and bytes on a CDR that have already been burned, remember? Since we now have a new version of the file, we also write a new file allocation table to the CDR that tells computers that are reading the CD that the location of the file is now located "here" as opposed to the previous version of the file located "there". You can no longer access the older version of the file, because the newest file allocation table does not contain any location of the old file. And computers automatically ignore the outdated versions of the file allocation tables, but read the most recent version.So let's say you start with a brand new CDR, and you burn a file called "mydata.doc". Lets say this file is 100 mb in size. The CD now has 100+ mb already burned, and something less than 600 mb still available for writing. Later, you decide that you want to write a new version mydata.doc to the same CD. A second version is added to the CD, and a new file allocation table is written. The CD still only shows mydata.doc and it still is only 100 mb in size (assuming you didn't change the size of the file when you made changes to it.) You think you still have just under 600 mb of free space on the CDR, right? Wrong. You now have less than 500 mb free. And if you repeat the process a 3rd time, then you will end up with only 400 mb free. So that's why Windows XP doesn't allow you to "delete" files from a CDR, because you can't really. I suppose they could have allowed you to write a new file allocation table without that file listed, but what would be the point? You still can't recover any of the space already used up on the CD. In fact, writing a new file allocation table with that file delisted would actually use up even more space (for the new version of the file allocation table), so why bother?But there's a way... IF you are using CDRW media and a CDRW-capable CDROM burner:CDRW's... These are special CD's that are truely rewritable. You can physically change the bits already burned on a CDRW after they have been previously written to. So CDRW media can be used just like any other rewritable drive (floppy disk, harddrive, etc). ...Provided that you are using a CD Burner that has CDRW capability. And you MUST be using an actual CDRW disc. If you insert a CDR instead of a CDRW, then you are bound to the normal CDR limitations. Most burners on the market today do have the capability to rewrite CDRW's, by the way. One important thing to note... You can usually only rewrite data on a single CDRW disc up to 1000 times or slightly less. That's because after that many "burns", the disc becomes unreliable/unburnable.So anyway, I'm willing to bet that you are using a CDR in your burner, and that's why you can't delete the file.Hope this helped!Jason

Also, it depends on the software and type of media/burner. You may need to completely erase the CD-RW before rewriting, or, you may be able to simply delete files like you would from a floppy or harddrive.I really like the DVD-RAM format - it's like having 4.7GB floppy disk which you can easily modify at any time. I currently use a couple of those for keeping my FS2004 backups up-to-date.

Jason:You explained it brilliantly. I am 101% ignorant about CDROM processes and never really understood why folks talked about "burning" stuff onto a CD. Now I get it!When I got this PC almost 3 years ago, DELL gave me a list 9 feet long with options, but I never knew what a rewriteable CD ROM drive was until today.Thanks a lot for taking the time to do this. I learned something new and important.Yay!JS

Dear Jason,Even for an old guy like me, who builds his own equipment, I have always had a weak spot of information when it came to cdr and cdrw, and now, I have all this new information which you so aptly wrote about. Not sure what you do for a living, but you could be a great technical writer, as most tech writers do their thing 6 levels above everyone's heads. Great job of providing valued information.Best,Clayton T. Dopke (Clay)Major, USAF (retired)"Drac"

Jason:Interesting that this subject should appear this morning.Last night, I did a backup of my wife's favorites, her address book, her documents and her msmoney.mny folders/files.I used NERO version 5.5.10.42 with the following procedure.1. First I did a total erase of a read and write CD (NERO full erase, not quick), and then checked that it was empty.2. Useing NERO EXPRESS I then copied the above files.3. I found that the money files would not read (Probably were good backups and would have if reinstalled on the harddrive). The other folders/files were fine.4. Decided to delete the money file. I highlighted the file, clicked delete (In NERO), and the file went away in the NERO window. However, when I brought the contents back up later, the file was still there. I tried this several times, and could not get rid of the file on the CD.Interesting considering the expected results and your summary huh?Thanks:RTH