No data from the CPU

Hello all,

i tried many ways and finally found this forum. SO hoping for a little help ,am posting this..

am using a desktop with celeron 2.18 GHz,512 MB RAM, 845 chipset motherboard,OS is Windows XP

The machine was working fine. One day to my bad luck i installed Directex9 in my machine.
After installation the system got restarted. After that it got stuck in the middle when it was on Windows XP logo screen. i restarted the machine. No data to keyboard and monitor But CPu made the starting sound and Lights wer ON.CD drive was ejecting also.But no data in monitor. I restarted again, replaced RAm slot from 1 to 2. System worked properly. I shutdown the machine and again restarted, CPU made the sound as starting and lights were ON, but no data to monitor.Keyboard lights also didnt blink as it used to do while starting up.

What will be the problem? i thought Ram pbm and i replaced it with new one. It worked for few times. After restarting it again showed the same pbm with new Ram also. Removed the Ram and switched ON pc, it made beep sound.

what i need to do now?what is causing this problem?Waiting for your reply..

thanks in advance,
Sooraj.S