I recently had shed-loads of problems when I tried to update my BIOS via Hewlett Packard (if that's still the right name now). The update failed, I was then advised to download it in Safe Mode and my laptop ended up in a mess. I couldn't even access the internet so had to use my old XP to post on Microsoft Community for help (http://answers.microsoft.com/en-us/windows/forum/windows_7-system/starting-in-safe-mode-co-incidentally-resulted-in/fb936966-374b-44ae-b085-6078bb0b1087). [Incidentally, in case it's relevant, the appearance of my screen changed after going back to normal mode - instead of the Microsoft Globe icon bottom left, there was "Start" in black font and the whole bottom bar had a white background.
I muddled through & eventually got System Restore to work using Services. After my system was restored to a few days ago, then had problems with NIS. First, error 3039, 6559 [is that one or two errors?] appeared. Norton Autofix sorted it then another appeared - 3035,6. Autofix could resolve it so Auto-Protect and Sonar protection were disabled.
I checked for and installed MS Updates. Two installed but KB915597 Defender failed. This was a code 8000FF - registry error. Microsoft Fixit 50202 resolved it and when I restarted, NIS was working fine, although I've lost the icon. (I'll shortly check my threads to see what you advised me when this happened the last time,)
So - everything now appears to be working but I remain uncomfortable as I don't know what caused the problem and whether it could happen again. Do the error codes suggest the cause?