Dear friends, I use windows XP + SP2 with the following configuration. MOnitor: LG 15" studioworks, MB: 845GVAD2 Intel original, CPU: 2.4 GHz Pentium4, RAM: 256MB , CD ROm: Samsung, HDD: Seagate baracuda 80 GB. NO sound or grafix card,I use inbuilt support of Main Board only .The HDD is 1 yr old and the system is 2.5 yr old. Internet: Dial up connection. since last few months, i m facing some problem like : My monitor screen suddenly becomes rectangular pieces of different color combination and nothing works there after . Neithr keyboard command nor mouse movement , everything stops and i need to force shutdown the system . It does not happen always or in every login . It happens sometimes and this z too much troubling as sometimes when i am online and doing somebrowsing and mailing , it also happens . Again saying , this problem always comes suddenly though it z not regular. In a month i experience this 3-4 times. Can any one tell what may be the reason. any kind of hardware failure or s/w failure.