I am facing a serious problem in my comp. When i POWER ON the computer it gives loooooooong beep. The monitor doesnt displa. After 5-6 attempts the comp. booted but after the WinXP booting screen the blue screen appeared giving message that there is some problem with the nv4_mini.sys and to prevent futher damage to it the system needs to shut down. I again booted and the computer atarted fine , but after a 10-15 min. working on it some fine black lines appeared for a oment and everything froze-keyboard,mouse monitor.Everything. Please help me sort out this problem as i am going thru this cycle regularly.