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Hi Lars,
ZA Free version 6.1.744.001 works well and is also before the bloat from CheckPoint.
I do not know if that will make any difference, though.
Actually, on my computer, avast usually appears on the task bar before anything else yet it causes my computer no problems. Sorry, I know this does not help you any but I do not know what to suggest since the other suggestions above were no help.
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