Computer repair involves a range of processes aimed at diagnosing and resolving hardware and software issues:

1. Diagnosis: The technician begins by examining the computer to identify the problem. This can involve checking both hardware and software components. They might listen for unusual sounds, check error messages, or run diagnostic software to pinpoint the issue.

2. Troubleshooting: Once the problem is identified, the technician troubleshoots to find the root cause. For hardware issues, this might involve checking components like the hard drive, RAM, motherboard, power supply, and other peripherals. Software issues could involve diagnosing viruses, malware, corrupted files, or operating system errors.

3. Repair: After identifying the issue, repairs are undertaken. This could involve replacing faulty hardware components like a damaged hard drive, malfunctioning RAM, or a failing power supply. Software repairs might involve reinstalling the operating system, removing malware, updating drivers, or fixing corrupted files.

4. Testing: Once the repair is completed, the technician tests the computer extensively. They check all hardware components, run diagnostic software, and ensure that software issues have been resolved. They might stress-test the system to ensure stability and performance.

5. Quality Check: A final check ensures that the repair was successful and the computer is in good working order before returning it to the customer.

Repairing computers can vary significantly in complexity depending on the issue. Some problems might be resolved relatively quickly, while others might require more time, especially if specialized parts need to be ordered or if the issue is intricate and requires thorough troubleshooting.