WE have a Lenovo Laptop with windows 10 and it won't play DVD's says no disk in the drive?

Hm

Either the disk is bad or the drive is bad. Both are very common.

First off make sure that your Lenovo laptop actually has a DVD player installed in it if it does try another DVD just to test it Windows Media Player will play most DVDs but you can always install the free DVD software then the manufacturer of your computer provides for free on their website or VLC media player

You may have played a disc recently on a different drive and it maybe looking at the wrong drive letter eg a USB drive or stick with a different drive letter. Because windows 10 does not play dvd's by default you will have had to install a 3rd party player, this may be subject to country restrictions or Media Rights. VLC player is free and works on windows 10 you could try using that instead but you can't easily break the rules around Media Rights or Country(region values).