What is Odyssey Client and how do I get rid of it?

I started up my laptop this morning after a friend of mine used it and my passwords and everything had been changed. I tried to log on and it kept popping up something called odyssey client. It wouldn't ever let me on. How do I get rid of this without being able to log on to my computer?
I already reset my passwords and everything.
It keeps trying to connect to a network, I don't know. Please, how do I get rid of this???
Thanks.