I wanted to upgrade my desktop from Business Edition to Ultimate SP1. I attempted to just run the upgrade, but it politely informed me that I needed to install SP1 on my Business Edition first. Well what sounded like a trivial routine task, ultimately rendered my Desktop completely unusable without an Operating System that would boot.
My desktop happened to show that SP1 had been downloaded via the Automatic Windows Update functionality, so all I needed to do was install. I let Windows do the SP1 install and at the end, it said that it was 100% complete. I shut down the PC for the night and the following day when it was restarted, it would not boot Vista in Normal Mode, Safe Mode, or otherwise. The OS decided that I had a "Missing or corrupt ntoskrnl.exe", please insert Vista DVD and repair the installation.
I figured, no problem, I will just run the repair routine which seems unusually common in Windows installations. Much to my dismay, I was presented with an error message to the effect of "This problem cannot be automatically repaired". That's it. Nothing else. Now what? Google, of course. Unfortunately there were thousands of blog posts with the same error message, but none of the suggested "hack" like fixes did any good on my system. Nothing of course from Microsoft.
Fortunately Microsoft is offering
free tech support for SP1 issues. I never recieved any response from the contact form (supposedly 24 hour response time). I did get about 1 hour of time from a tech representative on the Chat line. Ultimately the best response I got was I need to completely reinstall Vista, all my programs and data. He did give me information on how to do the reinstall using the custom setting to retain a copy of my data, which was helpful information, but it won't save the 16+ hours it will take to reinstall all my installed programs.
I have not tested it, but there were many references from other upset users to use the 460 Mb standalone SP1 install instead of the poisoned Windows Update version.