Computer repair is handled by a Professional computer repair Engineer. Typically, Suspected components, such as random access memory (RAM), hard disk, power supply or optical drive may be individually checked, troubleshooted or replaced if an error is detected. a hardware fault requires the physical review of a computer and testing for abnormalities. This usually requires special equipment and accessories to disassemble and reassemble the computer. Software-based computer repair issues are generally related to operating system (OS) configuration or updates, viruses and other software services. Similarly, installed applications, computer repair for Internet / Network issues allow a computer to completely utilize available and network services.