Hi

I have new laptop. First, it worked OK with Media Player. Then I installed some burner software such as AVIto\DVD,...
Each I click on Video DVD, it pop up window
" Windows Media Player cannot play DVD video. You might need to adjust your Windows display settings. Open display settings in Control Panel, and then try lowering your screen resolution and color quality settings."

I tried changing Media set up and uninstalling the burner software but the problem still exist.

Thank you for your instructions.

Best,

What version of Vista do you have - Home Premium or Ultimate?

Since you claim you could initially play DVDs via Media Player, I want to assume you've got Home Premium or Ultimate. AFAIK, only these two flavors offer built-in DVD playback support. Home Basic, Business & Enterprise versions do not; at least, not without a third-party DVD decoder present.

My suggestion at this time is to run System Restore & revert the machine state back to before you installed the burner application.