Page 1 of what is macrovision?

I can disable it on my dvd but what does it do?

If you connect your dvd to your vcr and record your dvd film on to a tape and then play that tape you will see the picture and usually the sound as well is distorted. i.e. preventing you from copying it satisfactorily.

This is macrovision, its there to stop you copying films basically!!

It also distorts the colours on your copy, going from normal for a while to VERY red/back to normal etc. This is to prevent you from making a commercially viable copy of a dvd & therefore preventing the major movieco`s losing money to pirates!