It depends on what you currently have. Is it a brand name PC or a home brew? As long as you have a PCI-E x16 slot, which I assume you have, and enough space for a new card along with an adequate power supply it really isn't to bad. It can just be more of a pain in the butt to manage cables in a smaller brand name case. If you have to replace the power supply I'd suggest a modular power supply if you want to make it easy.