Can a CD appear empty even if it has data?

I've had experience with this, and I can confirm that CDs and DVDs typically lose their data over longer periods (anything over three years), which can lead Windows to read them as blank. If you've tried a few drives and they still won't recognize the data, it's probably lost at this point.

Try using a program like ImgBurn on your Windows machine. It can scan the CDs and let you know if they’re actually empty or if they have data on them. That could save you a lot of guesswork!

There's something called CD Rot, which affects all kinds of CDs, not just the homemade ones. Over time, they can degrade to the point where they seem blank. In some cases, recovery may be possible, but you'd need a specialist. Be careful with those discs!

If you've got CD-Rs, you can often tell if data was burned onto them just by looking at the bottom side. The organic dyes used on these disks can degrade over time, however, which might make them unreadable. So if it appears completely uniform, it's likely empty, but degradation could be an issue too.

You can check if a CD has data by examining the underside. If the area starting from the center is darker than the outer edge, it's likely been written to. If the surface looks damaged, especially around the edges, that could indicate disk rot. If nothing looks off, try using a different disk drive that might better read certain types of CDs or DVDs.