Cooling and good power
If you’ve had a computer for a number of years you might notice its making far too much noise. Get a can of compressed air, and with the computer turned off and unplugged, give a light blast of air to the anything in the case that has a fan attached and/or looks like its designed to dissipate heat. A clean computer is a happy computer. It might be a good time to buy a new surge protection power bar as well. Given good power and cool temperatures a computer can last for more than 5 years.