computer help :/

[noob3]

my "family's" computer is really fucked up, it has so much random shit that tries to start up when you turn on it gets a blue screen unless you alt+delete alot of it off as it starts up. and it's not connecting to the internet anymore, i checked the plugs on the router thing and theyre all there i really dont know where to start i just want to fix their computer because it has the scanner and i want to get pictures of me and my girlie online

my mom says no to formatting because she wants to save stuff on there, but she dosnt know what she's talking about. i dont wanna bother cuz i dont know where the windows cd is : (