windows 7 x64 bit ultimate hanging on start up

[ayaz akram]

hi...
yesterday my son who is 1 years old switched off my computer from the power button. I didnt bother to check if it was all right till today and have found that the system wont boot to the desktop...as soon as the windows logo is there, nothing happens no matter how long i have to wait. strangely enough even without any hard drive in the pc it will still get to the logo screen and then nothing. I figured if the worst comes to the worst I could always do a clean install but again the screen hangs trying to load the installation disc. I have tried to start in safe mode but again the same problem. after bios post the writing on the screen says ''windows was unable to start up. this could be due to hardware or software changes and windows could have files damaged''...e.t.c. it the gives me the option to repair or start windows normally. I've tried both but it just keeps on hanging on load up.

system specs are:
asus p6t deluxe v2 motherboard
core i7 266 Ghz
ocz 3 ddr3 1333 mhz ram @12 GB
HD 4890 1 GB graphics card
x-fi elite pro sound card
wireless keyboard and mouse

even if I try a different hard drive im getting the same problem .

please please please some one help us out...

 

[Jonathan_King]

Try testing your RAM. Download a copy of Memtest86 and burn the ISO to a CD using Iso Recorder. Boot from the CD, and run at least 5 passes.

 

[ayaz akram]

but I cant get into my pc in order to do that...

 

[Jonathan_King]

Burn the CD using the computer you are using now.

 

[ayaz akram]

sorry I should have ex[plained...the computer i am using at the moment is the one i have the problem with...im only able to use the mother boards os to go online