DVD: Windows will read some DVD's but not others

[Guest]

I have Windows Media Player 10 and using WinDVD 5 Decoder. The system will
play certain DVD's but not others. DVD's that will not play, I try to read
them through explorer or the command line and get the following errors:
Format not recognized or i/o errors. These DVD's work fine in another DVD
player.
Do different DVD's have different formats. This is not a region problem
since they are all brand new local dvd's. I've reinstalled the driver that
came with the computer and still no resolution. Any ideas ?

 

[Cari \(MS-MVP\)]

If you are not referring to commercially made DVD movies, but home burned
disks, there are different formats.... DVD+R, DVD-R, DVD+RW, DVD-RW and then
the dual layer format disks.

 

[Guest]

I was not referring to home-made dvd's but rather those from a store.

 

[bxf]

I assume those that work and those that fail do so consistently.

Is there a common element/pattern here? For example, does one set or
the other have/not have, say, PCFriendly or something like that? Try to
explore them (on another computer?) and see if there are any obvious
differences betwewn those that work and those that don't. Also, I've
seen comments that state that some "very old" DVD drives may have some
incompatibilities with SOME modern disk production.