Firstly, the buzzing noise could be originating from the fans inside the computer. These fans work to keep the computer cool by blowing hot air out, and if they are malfunctioning, it could result in a buzzing sound. To solve this problem, you can try cleaning the fans. Dust accumulation on the fans can cause them to work improperly, leading to the buzzing sound. Cleaning the fans can be done by opening the computer case and using a can of compressed air to blow out the dust from the fans.

Another potential reason for the buzzing noise could be the hard drive. The hard drive contains the computer’s data, and if it is damaged or starting to fail, it can result in a buzzing sound. In this case, it may be necessary to replace the hard drive. If the hard drive is on the verge of failing, it is essential to back up all data immediately.

A less obvious reason for the buzzing noise could be the power supply unit (PSU). The PSU generates power for the computer, and if it is not working correctly, it can produce a buzzing noise. If this is the case, it may be necessary to replace the PSU.

In some cases, the buzzing noise could be caused by electromagnetic interference (EMI). EMI is a disturbance caused by an electromagnetic wave that interferes with the normal operation of electrical devices. In this case, try moving the computer away from other electronic devices, such as televisions or speakers.

Lastly, a buzzing noise could be a result of a loose component inside the computer. Check to make sure all components, such as RAM or expansion cards, are properly fitted and secured.

In conclusion, a buzzing noise coming from your computer could be the result of several reasons. It is essential to try and identify the source of the problem before attempting to fix it. Most of these problems can be solved by cleaning, replacing or securing certain components. If none of the solutions work, it may be necessary to seek professional help.