Here what could be the problem if system when switched-on it suddenly Shutdown just after 2 beeps.

Is the system in LAN ?
Did u overclock your system ?
Check the temps in BIOS if its in the appropriate range.
Plz describe the configuration of the system.

In my experience, fast shutdowns like that are usually either the power supply or ram.  If you have 2 sticks of ram, try booting with just one stick in place. Switch to the other stick if it still crashes to determine which is the bad stick. If that doesn't help, try another power supply. Remember almost all hardware problems are tested by swapping components one at a time until you identify the issue. Also, make sure you check the specs for your bios. Each bios can have a different meaning for their particular beep code. Dont totally trust what they say is the issue because I have had beep codes that turned out to be claiming one thing and it turned out to be something different.