Video out of sync with sound

[Best]

Not sure where to send this - on videos I have downloaded, or someone has
sent me, the voice is out of sync with the action. (Talking starts 1/2 sec
behind action!)
How can this be fixed, or why is it happening, or where should I be asking?

 

[Andre Da Costa]

Which application/s does this happen in? Have you updated your video and
sound devices? Have you scanned your system for vulnerabilities? What's the
system specification?

Try refreshing your codecs if you are using Media Player:
http://www.windows-vista-update.com/Windows_Vista_codecs.html