|The laser lens may be dirty. |
Clean the laser lens before you burn.
For a laptop drive, you can usually clean the laser lens easily, with e.g. a tissue or paper towel or a clean soft cloth, because it's obvious when the drive's tray is ejected and has no disk on it.
You must use a laser lens cleaning CD with a desktop optical drive, and with most external optical drives. If you don't have one, most places that sell CDs and DVDs have them - even some "dollar" stores have them for a buck or two.
The disk may actually have nothing on it. Compare what the supposed burned disk looks like on the burnable side to what a blank disk looks like on the burnable side - you can tell if it has data on it - if it looks the same as a blank disk, you didn't actually burn anything onto it.
Most burning programs have a setting that simulates a burn as a test - the progress of that looks the same as an actual burn, except possibly for a few words on the screen that indicate it's a simulation, but nothing is burned onto the disk if that's all that was selected - you have to select to actually burn as well.
Check your settings in the program.
If the settings in the program are correct, most if not all burner drives have at least two lasers - sometimes one laser, or the circuits for one laser, burn(s) out.
Also, most burning programs have a setting that can verify that the data on the disk is the same as on the source file(s) - it's a good idea to always use that - you will then know right away if the disk is faulty, right after the burn is finished.
All optical drives are a little, or a lot (e.g. some Pioneer models), sensitive as to which media - types and brands of disks - work with them and their firmware properly.
The manufacturer usually has a list of which media has been tested with the drive model and has been found to work properly on their web site, or if you add am optical drive yourself, there is usually a printed list of media that works properly that comes with the drive model.
That usually isn't a problem with CD-R media, but it can be a problem with other types of burnable disks.
E.g. The LG DVD combo models (burn and read both CDs and DVDs) I've looked up list only one media brand that makes burnable disks for all the types of burnable disks it can burn - a far east only brand marketed in other places as the Verbatim brand - that the drives work properly with. Individual burnable disk types have several brands listed.