Okay, here are my experience about this issue and how I can fixed it just a moment ago.
1. Uninstall "Acer Bio Protection" (means I can't use my finger print security feature anymore);
Found no more logon failure issue. I can login normally. But there is another issue, desktop doesn't not fully loaded, avast didn't starting at all, and system frezz in the middle of shutdown/restart.
2. Via safemode, uninstall avast 5 and use Avas uninstall utility after that (I though maybe there are some corrupted registry from previous avast 4.
.
3. Back to normal login, desktop fully loaded, and install avast 5 pro.
4. Avast didn't ask to restart the system. So I connect to the internet, put a trial mode on, update virus definition. Then restart after that.
Found login normally, system back with normal behaviour, no crash - no hangs.
But I wish I could use my finger print back
Thanks.
Cahya.
p.s: how can I get the key file with avast 5 pro, I have valid version 4.8 pro key for another more than 2,5 years. When I click "request conversion the v5 license" I came to website that asking me username and password - which I don't understand about it.