Windows 7 problem?

I think this is related to the Windows 7

My friend had just upgraded his VAIO from Vista Home Premium to 7 Ultimate (follows the steps provided by Sony)
Just now, something happens.

Windows 7 doesn't start. It stops at boot screen (animated Windows logo)
Already tried using Safe Mode, no avail.

Recovery Center- cannot on
Using Vista Install disc- doesn't start (it stops after Windows loading files)

Any idea anybody?

I think it's because of the motherboard, what do you think?

Thanks

But, the main prob is, he can't log in...

Anyidea?

No idea what the Sony instructions are. But rather than trying to fix that mess I suggest you do a clean install.

Thanks for both of you

It's kinda helped

But what happened are:
1. Starting up computer will just until the boot screen. No logon screen. It stuck there
2. He have tried using the Vista install DVD, but it doesn't start.

He wants it

Before this, he had installed Windows 7. But problems occur. So, he revert back to Vista. Then he changed to 7 again.

Add my vote to the clean install.