[rant on]
These issues with Avast and others you mention are one main reason I decided to go with MSE and Windows Firewall on my W7 systems and the new Windows Defender and WF on my W8 systems. Since doing so in Oct 2009 (when W7 was released), I've had no regrets, or security problems.
Only MS, as far as I know have a real incentive to rid the world of malware. And that incentive is to stop the
unwarranted and relentless blame and bashing they've been getting since the release of XP for security by misinformed or simply biased MS bashers and unprofessional IT journalists looking to sensationalize headlines.
And they do it by offering "free" anti-malware solutions. MSE/WD don't have ads trying to get us to upgrade to expensive solutions that not only cost you upfront, but keep bleeding you year after year with renewals.
Microsoft did not put us in the current security state we are in, the badguys did. Microsoft was complying (caving?) to corporate demands to keep XP compatible with legacy DOS era software and hardware. Microsoft was
forced by Congress and the EU to remove their planned inclusion of anti-virus code from XP because Norton, McAfee and the others cried and whined to Congress and the EU that MS was trying to rule the world. They were, but not the point. Norton, CA, Trend Micro, McAfee and others claimed it was their job to rid the world of malware and yelled "monopoly".
That was the one word Congress and the EU needed to hear so they threated MS with a forced split-up if they included anti-virus code.
We see now, almost 15 years later how well Norton and others have done.
Like I said before, they have no financial or business reason to rid the world of malware - yet the EU and Congress had blinders on.
And I note NO ONE, not even the bashers or real professional journalists predicted the explosive growth of broadband to the home. And NO ONE, not even the real security experts predicted the explosive proliferation of badguys and their malicious code - or how gullible we humans can be.
But since W7, MS has put security ahead of legacy support and what happens? Those same biased bashers bash MS because 10+ year old software and hardware is not supported. They don't blame the software developers for not releasing compatible updates, or the hardware makers for not updating their drivers. They blame MS for not building in legacy support for unsecure legacy products. They even blame MS because these 3rd party software makers force us to "buy" new, compatible versions of their products.
So MS is the villain either way apparently, but MS (and rightfully so, IMO) would rather be blamed for failing to support legacy hardware and software then for making insecure products. Too bad all these so-called wannabe security experts won't remove their biases and blinders to see the reality.
It is not just the anti-malware makers either. The big telecommunications carriers and ISPs refuse to block malware, spam, and spyware
at the source claiming that is not their job. But the real hidden agenda there is they want you and me to buy more [profitable] bandwidth, bigger routers and pipes from them instead of reducing the need for more bandwidth by blocking all the malicious code BEFORE it gets on the big backbones.
certainly not going to put many eggs in that basket either.
Regardless your primary anti-malware solution, we all should have at least one supplemental scanner to make sure neither we (as the weakest links) or our anti-malware solution did not let something slip by.
I use and recommend MBAM for that. And again, since going to MSE/WD, MBAM has found nothing got by.
[rant off]