In the boot-time scan settings I would suggest that you uncheck the Unpack archive files option. That will save a huge amount of time if your 1 million zip file isn’t an over exaggeration.

The avast boot-time scan report should be in C:\Documents and Settings\All Users\Application Data\AVAST Software\Avast\report\aswBoot.txt if you did a clean install of avast6 ?

If you did an update install of avast6 over or from the avast5 UI, then aswBoot.txt ‘should’ be in the location you mentioned.