Bottom Line: dbgeng needs to be included in the list of items that cannot be removed when Host Refresh is enabled in Compatibility. (v 1.5.0.6025.)
So, I just took my shiny new build of Win7 + NTLite and tried to upgrade my existing Win7. I thought I was being clever with this latest Preset because I found even more things to remove. Among them was Windows Symbolic Debugger Engine.
Then I tried doing an upgrade to my running Win7. I had done this last week without problems. But this time, when Setup rebooted into the GUI mode, I got an error message that dbgeng.dll could not be found.
But I had enabled "Host Refresh" in Compatibility. Apparently the Debug Engine is not locked.
Just did another build and going to try the Upgrade again.