Fortunately, there are hardware upgrades that can extend the useful life of your current computer without completely draining your account or relegating yet another piece of machinery to a landfill. Some upgrades are more expensive than others, and if you did all of them, you might as well buy a new machine in most cases. But replacing one or two components, especially the oldest part or the one you’ve determined is causing a bottleneck, can provide impressive performance improvements while remaining cost effective.