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1. Update driver
2. Maybe weak laser - in that case some CD/DVD are detected and few others are not
3. Did you try the same CD/DVD on some other computer
4. And finally, which I hate to write, maybe this drive needs replacement. They are not very expensive.
Happy New Year!!!
Thanks for your input. I did try to update driver but Windows said it was up to date. I will try CD/DVD in my laptop. It may need replacement but is almost 6 years old so may buy new computer and just use my thumb drive to store info for now.