As the title suggests, my Windows HP Pavilion Entertainment PC (I think, I'm just going on the label under my keyboard really. No idea with computer models to be honest) is having an issue where I'll plug in headphones and it'll put sound through the headphones, but still throw out sound through the speakers, something that is very annoying in a household with other people in it. And, when I try to change from the speakers to the headphones, which are working perfectly fine too, it doesn't give that option at all. And, when I have my sound muted, sound still plays on half the time. THen, there's a problem were I need to restart my computer if I close the lid for it to work.
Is this computer just so old that I need a new one already? Is it a bug? Is it something that can be easily fixed? How should I go about this problem?