If you have a computer that is running Windows 7 or Windows Server 2008 R2, which crashes during the startup process before you are prompted for user credentials, then this article may interest you.
In addition, you may also receive the following Stop Error message or Blue Screen Of Death:
STOP: 0x0000006B (Parameter1, Parameter2, Parameter3, Parameter4) PROCESS1_INITIALIZATION_FAILED
This occurs because the Bootcat.cache file, located at %SystemRoot%\system32\codeintegrity, is corrupted or because the size of the Bootcat.cache file is changed since the last successful start.
To work around this issue, start the computer from the disc drive or from the USB drive by using the Windows installation media. Delete the Bootcat.cache file, and then restart the computer.
Microsoft has also released Fix314438 to address this issue.
To download this hotfix and for more details visit KB981833.