I've hunted all over the net to fix this but no joy and have been suffering with this issue for a few months now. Maybe someone can help or offer advice?
I had Windows Vista Ultimate 64bit edition installed on my home computer and formatted my drive and did a clean install of Windows 7 64bit. However, my PC will not boot and shows the following error:
'A recent hardware or software change might have installed a file that is signed incorrectly or damaged, or that might be malicious software from an unknown source. If you have a Windows installation disc insert the disk and restart your computer. Click "repair your computer" and then choose a recovery tool. Otherwise, to start Windows so you can investigate further, press the ENTER key and display the boot menu, press F8 for Advanced Boot Options and select last Known Good. If you understand why the digital signature cannot be verified and want to start Windows without this file, temporarily disable driver signature enforcement.
File: \windows\system32\winload exe
Info: Windows cannot verify the digital signature for this file'
When I press enter to continue, I get take to the "Select OS" screen and the only option listed is "Microsoft Windows Vista". I have tried repairing countless times to no effect. I have checked the digital signature of "winload.exe" and it is signed. Also byt the way, my copy of Windows 7 is a purchased legit copy.
Strangely, if I leave the Windows 7 64bit install disk in the drive, my PC sees the DVD on boot up and says "press any key to boot from CD...". If I don't boot from CD, Windows 7 loads fine!
I've also had this problem, mine even sometimes went to this screen when booting up from the DVD, but randomly it would go to windows setup.
To fix it, try this (I'm doing this from memory so excuse me if menu names aren't exactly right):
* Start Windows 7 Setup by booting from the DVD
* Select "Repair My Computer"
* Select you Windows 7 installation from the list
* Select "Open Command Prompt"
* Type "bootrec /fixmbr"
* Then "bootrec /fixboot"
* Remove the DVD, reboot your PC and hopefully it'll work again!