Recorded photos from Pictures on pc to dvd-r. The dvd player says "disc error". Other discs play on the machine. Recorded photo dvd plays on the pc.

SOURCE: DVD/CD RAM Devices

try some 3rd party software, nero, magiciso, poweriso,,,to burn discs,,,

Or
try using XP service pack 3..
good luck.

SOURCE: LG dvd player DP281B shows disc error

if you have USB PORT. JUST remove the disc from dvd unit and plug in a usb pen drive with usb port.
if you haven"t.USB PORT JUST BUY IT FROM LOCAL ELECTRONICS SHOPS AND FIT WITH YOUR DVD player.

SOURCE: Recorded DVD will not play in another player

if you record something in VR format, then it wont play in your dvd machine despite what kind of dvd you use. You need to record in "video format" if your camera supports it. Problem with that then is you cant edit or delete scenes. Also you must finalise your dvd before sticking it in your dvd machine in order for it to play. You can unfinalise it later if you want to add more stuff to the dvd.

I bought a samsung dvx100. I am using dvd-RW disc and am restricted to recording in video mode only. If I record in VR MODE it wont play on dvd machine :( so i cant edit or delete now either.
p.s dont forget to finalise the disc.

SOURCE: dvd "unknown disc" message coming up

When Your DVD shows "LOADING" for quite some time and then if shows "UNKNOWN DISC" or "NO DISC", Open the cover of your DVD Player, Remove the flap over the disc by opening the screws. Remember that you are not keeping your eyes perpendicular to the lens. Now take Colin liquid in an ear buds and rub over the lens. Now with dry end of the bud, rinse it and make it dry. Keep the disc in the space provided for. Put on the Flap over the disc. And try to run it. I hope this would work fine.

SOURCE: How do I finalize the mini-disc in my Canon DC201 camcorder?

There are two different formats to choose, Video and VR.
If you choose Video, can cannot edit the recorded material and you can finalise the disk on the camcorder which will create a menu for you.
In VR mode, you can edit but not finalise. You will need to create a menu using software.