The term hardware refers to the physical components that make up a computer. These components may be mechanical, electrical, electronic or magnetic. The term may also be used to describe peripheral devices and cables. Software, comparatively, refers to the instructions or programming that make the computer perform tasks. Hardware is tangible, whereas software is intangible.
Internal computer hardware includes the motherboard, central processing unit (CPU), random access memory (RAM), read only memory (ROM), modem, hard drive, optical drives such as the digital versatile disk (DVD) and compact disk (CD) drives. External hardware includes the monitor, mouse, keyboard and speakers. Peripheral devices may include a printer, scanner, a network router or access point and universal serial bus (USB) devices.
Modern desktop computers are modular, which means that they have standardized parts that you can replace or add easily. Laptops are modular to a lesser degree. Most computer motherboards have multiple RAM slots and peripheral component interconnect (PCI) expansion slots. Some newer motherboards may also have an advanced graphics port (AGP) and PCI-Express slot, as well. Motherboards typically also have onboard audio and video chips, which can be disabled when you install a video or audio upgrade in one of the expansion slots.
The keyboard, mouse and drives can be used to input data into the computer. The hard drive is semi-permanent data storage that retains its data after the computer is deactivated. RAM is temporary storage that is erased every time you turn the computer off. The CPU processes information from these sources. The monitor, speakers and printer can output the processed information in a way that the user can understand. In order for computer hardware to function properly, all devices must be securely and correctly attached. Also, all software, including the operating system and device drivers, must be properly installed.
Most computer problems are caused by software, not by hardware. In many cases, the error is only in memory. In this instance, the best solution is to turn the computer off, leave it off for at least thirty seconds, then turn it back on. This erases all of the memory so that you can restart the computer with a clean slate. Also, a missing or corrupted system file can mimic hardware problems. Changes to the system registry and lost device drivers can cause hardware to malfunction. To resolve these problems, reinstall your device drivers, use System Restore or repair your operating system installation. Also, run a complete hardware diagnostic to find potential causes of the problem.
Once you have implemented these solutions, you will have a clearer idea of whether a you're really having a hardware problem. If you still experience a persistent problem or repeated error messages after implementing these changes, back up your data, format the hard drive and reinstall the operating system.