When I connect USB Stick to my PC, does Avast protect me? I mean does Avast scan the files on the USb Stick just at the moment when USB Stick has been plugged in?
No. It only scans active things, such as an autorun malware which tries to infect pc when you insert usb stick. And if you run/open a file on your usb, then of course the standard shield will scan it as well. Apart from these cases, you have to scan your usb drive manually. But passive things has nothing to do with protection, you have to perform manual scans to detect them. avast! does protect you well from active threats.
Yes. You’re protected.
But no, only the files that are automatically started are scanning.
If all the usb stick files were scanned, it will be a overkill (unnecessary).
Oops, mevcit was faster 
hm, but trojan horses often intrude automaticlly via USB :-\
These will be scanned and blocked.
Get the protection from Old McDonald’s Farm with Autorun Eater:
http://oldmcdonald.wordpress.com/
if I have to get extra tools against every danger then this is crazy :o
And tools over tools doesnt end good in most of the cases…
Hi cska133,
You don’t need that, right click the blue ball, go to global settings, general settings and tag that avast scans all peripherals, no sweat, and then read what I have written here:
http://forum.avast.com/index.php?topic=48885.0
pol
Its called Layered Protection.
No anti virus application is 100% effective against the prolific malware writers today. 
I use several layers 8) :
- avast! anti virus
- Autorun Eater to remove malware from USB sticks
- HOSTS file managed by HostsMan to block known malware sites
- Malwarebytes Anti-Malware (MBAM) to block malware from installing
- Microsoft Security Essentials (MSE) to block Microsoft known malware
- WinPatrol Security Monitor to monitor what the others miss
Hi YoKenny,
I agree with you fully and I also act accordingly. Notwithstanding that you can also fine tune avast through its settings to better do your bidding as I demonstrated above,
polonus
Do that then you can’t safely remove the Flash drive
Another overlooked consequence that I didn’t realize could happen until it happened to me - shorting the USB controller out. Believe it or not I actually fried a motherboard by removing the USB drive without Safely Removing Hardware. It can happen…
http://www.tomshardware.com/forum/236841-31-safely-remove-hardware
The only time NTFS is needed is if you want to store files larger than 4GB so if you have Flash sticks that are capable of using NTFS then I would be very very careful removing them If I could not use Safely Remove Hardware.
I have USB stick that I use frequently. It opens with Auto Play and Avast scans normally like it would any other executed file or program. Then when I open a file Avast also scans normally. If a virus executes when you plug in the device you will be protected by Avast, at least that what it’s designed to do. I have a lot of confidence in Avast, it hasn’t let me down so far. 
if I have to get extra tools against every danger then this is crazy :oNo, only a little crazy. ;D As YoKenny said, it's part of what's called a layered protection. The serious security folk will cover the different vulnerabilities in Windows with simple, light, and effective applications specific to their use. So, fo example, you use a firewall to prevent unsolicited inbound "probes". An antivirus to scan stuff that downloads. Maybe a hosts file to prevent known bad URLs from connecting. Something to check your software is up to date. And, in the case mentioned, something else to monitor autoruns. (It's one of several autorun monitors/checkers.)
And tools over tools doesnt end good in most of the cases..Not my experience at all. Of course, you have to choose the right tools. ;)