Ow thankx.

Go to the CMOS Setup and reset everything to the Default settings. See if that recognizes your HDDs. Make sure they're all set to Auto. Then see what happens. Another try would be to press F8 at startup (after setting CMOS to Default) and chose Safe mode w / Networking. Will it boot then? If it does then you've got a video card problem.

Also set BIOS to default and see its works or not.

I dont thnk i will try that one but thanks

Whats the difference between CMOS & BIOS? No function key works. Everything i tested in BIOS but it did nothing. The problem started just after i tried to load ctfmon.exe , lass & winlogon.exe manually by msconfig - these files were quarantined by anti-malware (all anti viruses does this aswellas antimalwares and antiviruses deletes more files later on - one more thing *all shows caution of svchost on first scan but if its deleted then problem will start* DIFFICULT TO UNDERSTAND ANTIVIRUS COMPANIES POLICY ! As i guessed it correctly, only option left was boot from pendrive. I did it yesterday night and its ok now. Video card is working properly like every other things.

So set BIOS

Apply all the settings in the BIOS to its defaults..If even after that prob exists, try 2 update ur BIOS..

Whats the difference between CMOS & BIOS? CMOS Complementary metal oxide semiconductor (CMOS) is a type of semi-conductor chip that holds data without requiring an external power source. In a personal computer (PC), CMOS holds the basic instructions the computer needs to initialize its hardware components and boot up. These settings are known as the basic input output settings (BIOS) BIOS A BIOS (Basic Input/Output System) is an 'electronic set of instructions' that a computer uses to successfully start operating. The BIOS is located on a chip(CMOS) inside of the computer and is designed in a way that protects it from disk failure.