Well i guess i had this computer for afew years now and afew days ago my pc just started making a noise like you can hear it running but it used to be a lot quiter any sujestions would help.
Could be any number of things from major to minor (and hard to tell for certain from here). Start with something simple and free: open the case up and give it all a good vacuum out. Be careful with fragile stuff and be sure to ground yourself out before zapping anything with static charges. See if the sounds go away. ie. - Dirty in/outlets can make your fans run in high gear.
also dust, dirt build up on the fan blades can cause noise. Be sure to wipe them down, give them a spin with your finger to see if it still spins fairly freely. There should be some resistance. But not a lot. Drive and card screws can loosen, tighten them, but don't over tighten. Look for cables contacting anything. Kind of like a rattle in a car, it usually a small thing. Good luck.
Take the case side off,power it up and see if you can isolate the sound to a certain area.Don't forget the power supply and by all means Be Careful!