Working on a customer's Vista machine, we started the install for Service Pack 2 and walked away. When we returned, it was in Startup Repair after having failed to start.
We then loaded Windows normally, and it loads to a black screen with cursor (before profile selection), then fades out and reboots. No errors, no information.
We've tried disabling automatic restart on failure, and it still reboots. (No BSOD)
Safe Mode does the same, Last Known Good Configuration does the same. Attempted a System Restore to the restore point prior to installing SP2, and it restored successfully. However, the issue still remains.
We have tried every solution we could find while Googling, including renaming \windows\winsxs\pending.xml, but this file does not exist.
This isn't the same issue as the "black screen with cursor" which we've experienced before, but in that case it does not automatically restart.
We've run the following command from recovery console, which was found while Googling:
start /w pkgmgr /up:VistaSP2-KB948465~31bf3856ad364e35~x86~~220.127.116.1105
Did not give an error, but did not resolve the issue.
We're at our wits end, and are hoping we can fix this without having to explain to the customer what a disaster this has become.
I know there were all sorts of issues with Vista and its service packs back in the day, but this issue is a new one for us.
We had gotten to the point where we just tried "Disable Driver Signature Enforcement" for the heck of it. Surprisingly, the OS loaded. Nothing of note in the Event Viewer, the system reports it is running SP1. There are no device drivers that report any problems.
The system will only boot using this option, and this confuses me even more.