Windows 7 wont start.. unable to get to safe mode even!

Hello All,
I am running Windows 7 RTM on a 1.75Ghz, 3Gb RAM box. Windows 7 was working fine for me, but this morning i just restarted because i thought it was acting slow. It had a proper shut down(I use verbose mode..)But then it never restarted. It just showed the HP logo and stopped.. I am even unable to get into the safe mode box(by pressing F8). I have a windows Xp bootable CD right now... and that doesnt boot either (Yes, I have ensured the booting order is correct.) What could be the cause?
Is it a hardware failure - As in harddisk crash? Because the computer just sits idle!! Strangely, I went to BIOS and did a disk diagnostic test which it passed.. But the harddisk LED didnt blink during the test(It should blink right?)... Please help me, i am really stuck here...

Some kind of bios setting. Check to see the plug and play os is set to yes. If that's not the cause, use "standard optimized default" as the global bios setting and see how it carries on.

Can't hurt to actually update the bios from the motherboard manufacturer's website too.

Even boot from USB/CDROM is not working How do i update the bios setting in this case? All i see is the logo.. and Boom.. Blank. Dead. Though I am obviously able to access bios...

shanu said:

Even boot from USB/CDROM is not working How do i update the bios setting in this case? All i see is the logo.. and Boom.. Blank. Dead. Though I am obviously able to access bios...

Remove all unnecssary components from the system that are not needed to have the most basic functioning machine.

Add them later, one by one, until the problem comes back.

How do I remove any component from the system? I am simply unable to access my machine I press the power on switch... the Manufacturer logo comes up.. and boom. BLANK. no cursor. Nothing.

I re-read ur message, and maybe Did u imply hardware components? I have a laptop.. So maybe fiddling with the parts this way might not be a very wise idea... But it HAS to be a hardware problem, right?

yes ,ur Hardware of compuer has anything wrong…