dvd won't play on pc

[kags]

I have tried to play the Kung Fu Panda dvd on my pc for my daughter to watch, but the pc doesn't recognise the disc is there - if I click on the dvd drive it says "please inset a disc". I have tried various other dvds with no problems at all - surely the new copy protection doesn't extend to not even being able to play it on a pc? It's a genuine dvd - not a copy.

[Ethel]

Is it the right format - for example is the disk blu ray and the player standard?

Is the dvd the right region?

[kags]

yes, correct region and it's not a blu-ray. Very mysterious!

[Ethel]

Does the dvd play on the tv?

[kags]

yes, plays with no problem at all, and all other dvds play on the pc.

[rojash]

It's not the blue ray version by any chance?

[rojash]

How weird - I swear that none of the earlier replies were there when I posted!