hanging

from few days it is giving me problem, it is hanging so often. tell me a way to rectify the problem.

I have a Pentium 4 3.0 GHZ processor with Intel 865GB Motherboard, 512 DDR RAM of 400 MHZ, 40 GB HDD, NVIDIA GFORCE MX 4000 AGP card, Frontech Smart Pen graphic pen and other computer accesories using Microsoft Windows XP professional. Its a new machine and worked well for about ten days. But...