hi, I'm new to the site and i would like to start off by saying hello to everyone. So my friend sold me his computer to me about 5 months ago, and everything was working fine. About 3 weeks ago, i started having trouble watching videos, and playing my video game that i have been playing for awhile now. I looked under device manger and it is listed that my multimedia controller and multimedia video controller are not working and have exclamation point and question marks under other devices. My friend who sold me the computer built it himself, and I'm not very technical so i need some help to figure out what exactly what i need to do in order for the computer to be back to normal. If someone could please help, thank you.