Whilst an old program version is supported, that is essentially limited to receipt of virus definitions.
Unfortunately since there is no further program development, if this were a startup problem with that program version, it is highly unlikely that program versions of that age are going to be updated. That after all is the likely reason why some people found that their program update was automatically updated despite their program setting, to get around a program problem/bug/feature in some of the old program version/s.
I don't know how your problem might be resolved.
Short of using the latest version, which still receives program development and customising the avast installation (not installing elements that you don't want) I don't really know how your matter can be resolved.
That said the only thing that would be going on close to boot is likely to be avast checking for virus definition updates (VPS), so there could be a possibility to delay the auto VPS update. That is a stab in the dark as there is no way to know for sure if that is the cause.
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Delay Auto Update - Not sure if this is the same for avast7, but this was in avast8, you need to edit (using
notepad)
avast5.ini the
[InetWD] section of the, C:\ProgramData\AVAST Software\Avast\avast5.ini. Win7, location, this folder may be hidden, you may also have to run notepad.exe as administrator to prevent UAC intervention.
- Broadband connections, add this line:
AlwaysConnectedWaitSeconds=120 and
AssumeAlwaysConnected=1 if not present (or edit AssumeAlwaysConnected=0 to AssumeAlwaysConnected=1)
[InetWD]
AssumeAlwaysConnected=1
AlwaysConnectedWaitSeconds=120
When complete save the changes, avast's self-defence module will ask for confirmation, etc. answer Yes. You can extend this duration if required.