Particularly Nero. I don't use Nero to burn or play videos, but they have an excellent diagnostic function.
I use WinDVD for displaying video files (excellent time slider function) and I use GOM player to play video files (handles all file types and formats very well).
Multilple packages also allows me to try another program when a particular file is giving me trouble. Is it the file or the program or oh, no - Windoze?
A rather obvious possiblity is that you have started using faster DVD blanks (8x, 16x instead of 2x or 4x) but I hesistate to insult you with such a simple suggestion. Kind of like telling you to check to see if your PC is plugged in.
It may be too late for this but if you can remember having made any changes just before this started to go south on you, that could be a clue.
BTW, I avoid using the computer when it is burning (or verifying). Theoretically Windoze can handle it but ... you know Windoze.
I have two PCs that are identical and sometimes that helps with diagnostics. It certainly helps when burning DVDs. But I digress.
Another possibility is that the lazer in your DVD drive is going south. They do wear out and can bring everything to a crawl when they begin to fade.
There probably 50 more things that could be happening, but maybe I've given you a start on finding the problem.
I always recommend that anyone who is having CD/DVD problems consult the geeks at http://www.cdfreaks.com/. They have thousands of member worldwide and really know what it's all about.
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