Most computers come equipped with a hard drive to store applications and documents. Hard drives have dramatically dropped in price over the last few years, to the point where few systems are even offered with anything less than a 10 gigabyte (GB) drive. High-end systems commonly offer storage capacities as large as 30 GB.

If this sounds like a lot of storage, consider that applications now routinely take as much as 10 to 25 MB apiece. An operating system such as Windows 98 will occupy as much as 200 MB - or even more. Complex files such as sound, graphics, or video can swallow up to 100 MB of storage space.