Great Forum you have ... I am a newbie to this forum.

I have a couple of CDs (CD-R & CD-RW) that I have used to store data files at work. The PC at work is a desktop HP Pavillion a1330n - Windows XP.

I have burned several small files to the CDs successfully to transfer to my home PC and another laptop.

When I burn a file to the CD from either my home PC or the laptop - and then try to burn other files afterwards to the same CD ... the CD capacity that is recognized by any of the PCs has been reduced to the point where the CD appears to be full capacity.

However, the total file size on the CD is very small and there should still be plenty of available - unused capacity.

For example: after burining CD on different PC - the total availabl ecapacity is 237 Mb, instead of the normal 700MB and the total used space is also 237 Mb.

Has anyone come across this problem and is there a way to reset the CD properties to the original capacity?

KirkC

First of all, a "CD-R" is a "write once" medium. That means, once you write to it, it stays there and never goes away, reducing the available capacity.

Because you are not "finalizing" the disc, you do leave it open so that you can write more to it later. And that's fine, but each time reduces the available space on the disc by whatever that file size was. A CD-R is not the same as other re-writable media such as a hard drive, a zip drive, a floppy drive or even a CD-RW. Each time you write to a CD-R, it's treated as a session. If you write the same file to it again later, it just creates another session and the file is written again - same name and all, but it is just part of another session on the disc.

This shouldn't be the case if you use a CD-RW, unless your burning/writing program does not treat it as a removable, re-writable disc which can happen. It should actually overwrite any exsiting file with the same name and the capacity should not be accumulatively reduced, unless the file is just bigger.

Hope that helps explain things a bit.

Joel

Joel:

Your explanation makes sense - but not sure it addressed my exact issue ...

It makes sense that each time I write to the CD-R, it will decrease the amount of available space by the size of the files that were written.

However, what is also happening is that the total capacity of the CD-R has been decreased from 700MB to 230+Mb ... yet, the total amount of all the files on the CD-R is only 328 Kb.

Somehow, initially writing files to the cd on my PC (Win XP) at work and then writing more files (different names) to the same cd on another PC (Win 98) at home causes the total cd capacity to decrease after writing the files using the home PC.

What should occur is what you stated in your earlier reply ... the 700Mb space available should decrease by the size of the files burned .... and also leaving total total capacity at 700Mb ... not reducing total capacity to 230Mb.

This example shuold occur: 700Mb less 328Kb = 699Mb of available space

However, this is occurring: 700Mb changes to 230Mb less 328Kb = 229Mb of available space

This also happened to a CD-RW disc as well.

Doesn't make sense for the cd's total capacity (not available space) to be reduced. Somehow, information about the capacity properties of the cd is being modified ... I am not sure how to explain it technically.

Is there some kind of stored information about the cd - such as FAT table or cd TOC file that is possibly being modified when I use different PCs to burn data files?

You also have to allow for Lead in and Lead Out data (for each session), but that's generally only about 10% of the CD (roughly).

It doesn't explain your situation.