Laptop Trouble

Hey i just got a new HP laptop. I can watch videos that were alreay on the laptop or on youtube and stuff like that. but when i try to transfer video's from my desktop computer and download some videos, such as avi files and stuff like that i just get sound with no video. i was hoping/wondering if anyone possibly knew what was wrong. Thats for the help in advance

When you say "no video", do you mean the video screen is blank, or scrambled, or does it go to that light show thing that the Windows Media Player does when you play an audio track?

I'm not too good with computers, but I'd recommend getting the newest versions of whatever media software you're using on the laptop for starters, and then we'll take it from there.

When i play it on vlc player the screen is completely black with audio and when i play it with media play 9 it gives me audio with that flashing bars and lines, like when you play music. Video works when i play a dvd movie from the drive.

Yeah i got it. It was a codec i didnt have i just needed to download the new vlc player and it worked thanks again for anyone who tried to help