Upgrade Requirements When you buy a desktop, one of your main goals is that you want it to be upgradeable. That means the following can easily be removed and replaced: hard drive memory CPU video card sound card If any of the above cannot be upgraded, you are buying into a closed system like a laptop. All laptops are closed systems because their video and sound cards cannot be upgraded. You should avoid all desktop systems that have the video controller or sound card integrated - soldered onto, the motherboard (like Intel Whitney and 810E chipsets). Manufactures do this to save them money. It does not save you money because you can’t remove it and sell it to someone else, you have to play with jumpers on the motherboard to disconnect it, and you need a free expansion slot in your system for a new card. Free Expansion Slots A free expansion slot is a long electrical connector on the motherboard that is empty. Expansion slots are needed to plug in additional devices like modems, disk controllers, MPEG cards, etc. There are three flavors of expansion slots: ISA, PCI, and AGP. ISA slots. The original 8 bit slots from the IBM PC. They are mostly used now for modems and older sound cards. Soon they will be extinct, but right now, you need a couple. PCI slots. The newer 16 bit slot (twice the transfer rate of the ISA slot), should be used for your main video card (unless you have an AGP slot) and any additional hard drive or SCSI controllers. Basically, any device that needs to be fast should be in a PCI slot. AGP slot - Advanced Graphics Port. These are found on newer Super7, Celeron, Pentium II and Pentium III class systems. If your system has an AGP slot you should have an AGP card. AGP cards can either be double speed (2X) or quad speed (4X). Make sure any computer system you buy has at least one or more free PCI expansion slot for future upgrades. Free ISA slots would only benefit those with older add in devices. Free Drive Bays Free drive bays are necessary to add additional hard drives, Removable Drives, CD-ROMs, or DVD players. An option for slower devices is to use the external USB port. Know What You are Buying The slimline, integrated, compact, and spacesaver type desktop systems should be reviewed very carefully for soldered on components, free slots, and free drive bays. When in doubt, stay away from compact or spacesaver systems.