Change the existing computer and are looking to increase with high performance, capacity or latest features should consider upgrading components before shelling out for an entirely new PC system. The appeal of upgrading is that it lets you improve your system for much less cost. It can also save you considerable time and hassle compared to the difficulty of reinstalling all your software and applications on a new PC. Upgrading a PC is a huge subject unto itself, and one I am not going to be able to do justice to in a single page here. Some upgrades are very easy to do, even for someone who has never seen the inside of a computer case: for example, adding more system memory. Other upgrades require considerable expertise and bring you much closer to the realm of knowledge needed to build a new PC in the first place: for example, replacing a motherboard. There is a fine line between upgrading and building a system, when you are looking at major upgrades. If you are buying a new PC and are thinking you may want to upgrade it later on, purchase a system with this goal in mind. If you don't plan to upgrade your new PC, then you shouldn't pay extra for a system that has upgrade options built in.