About Nero Burning (Again)

I just experienced a bad thing using Nero Burning. I have a cd that contain about 500 MB data and applications burned by Nero 5 few months ago (I didn't finalize the CD). A couple of days ago I added some data onto it to make the CD contain about 650 MB. But after I burned those additional data, I can't access my CD at all. Anyone has an idea what should I do? Is there any way to make my CD accessible again? Thanks

 

Multi-Session CD-ROM?

It sounds to me like your CD-ROM probably doesn't support reading of multisession discs....and since you burned info to the disc at one point, then added more later, you created a multisession disc, whether you realized it or not

1. Have you tried the disc in a regular CD-ROM as well as your burner?
2. Are you sure you closed the disc after the second burn?