Why does my computer twitch when I turn it on?

I just got a Dell Inspirion M… something.
Ive had it now for about a month or so.
I watch a lot of tv shows online and so most of the time I like loading them and then hibernate my computer. Then later on the day when I have time thats when I usually watch them. But with this computer its so strange because when I turn on the computer and click play on the show, the sounds plays but the video just flashes on that same scene again and again. I have no clue why its doing this. It’s usually a problem for me since most of the times Im always places where is isn’t internet and I would like to watch something but I can’t refresh it because I have no connection to internet.

p.s it never used to happen with my older computer my little LG notebook. I could load lots of shows and just watch them on the go like in the bus on my way home. (mind you I don’t download, I watch online and let it buffer so it wont always be stopping to buffer)

Hope you guys understand…