Computer Suddenly freezes

M computer suddenly freezes in the middle of usage. The only thing I could do is to restart the PC. When the PC freezes at the same time I am playing music, the speaker will sound like this, "brrrrrrrrrrrrrrrrr"I already tried some of the solutions I found on the net, like cleaning the inside of the CPU of dust, etc. etc. I already reinstalled my OS (XP by the way), and updated my drivers (Graphics, Sound, Lan). These were not solutions after all.

What other things could I do to stop this immature freezing of my computer? It really bugs me off when I am doing something Important in my PC like assignments and projects. A hard reboot is the only way I could do. I want to try other things to prevent this from happening again. It is really a pain in the @#!

Please help me. I have a 14 month old Pentium D 3.0GHz, 1GB ram (2x 512 Jetram DDR2), 256MB video memory (nVidia 7200 GS), 80GB HDD, ECS P4M890T motherboard, 2 optical DVD drives,and a 550 watt PSU.

By the way, m PC has no brand because it is assembled in a shop.

Thank you