If I'm watching a movie on my pc, record it and post it on youtube, will it count as copyright?

If you do that you'll be breaking the law. You do not own the copyright if you make a copy... even if it's a copy of a copy. Imagine if you write a book and I then rewrite it (and then photocopy it say). Is it now MY book, can I sell it to make money? Can i put my name on it and say I wrote it? of course I can't and the same goes for anything else, photos, films, comics, etc etc