I use PC with mother P4M800PRO-M , the fan it have a loud sound what can i do to solve this problem , thanx

Is it the CPU fan, chassis fan or power supply fan? In any case, it might help to clean the fan with a soft brush. To prevent dirt from getting everywhere you can use a portable vacuum cleaner or a regular one, provided you have unplugged your PC and wear an anti static wrist band, or, if you don't have one, keep a hand or the side of your arm touching the chassis' metal during the process.

Also, it could be due to something in the fan's way... In this case you should watching closely if this is happening and correct anything out of place, if possible.

You can also try to slightly tap the center of the fan while functioning. You must be extremely careful while doing this in order to prevent any damage.

Hi, your computer should have several fans inside the CPU box, at least one on your CPU, another one on the power source and there might be a box fan and a graphics card fan. You must try to find out wich one the making the noise and replace it. Whether it is faulty or is of bad quality, they are so cheap that the best thing you can do is replace it. It can be done at home by you, but unless you know what you are doing, I guess it is better to send it to a repair shop. Regards.

Just disassemble the fan and heat sink from the motherboard clean it and assemble it again sometimes processor fan cable also mesh with fan makes the sound checks that too