Should I be concerned

Hi all,

I would like to know if I should be concerned or not?

I ask this question because the other day viruses and spyware found their way onto my machine and Avast never detected them, I scanned a USB stick before using it and there was a virus on it. Usually as soon as I put removable media into my computer Avast scans it and a pop-up comes up and says that threat detected and blocked but on this occasion nothing happened I scanned and virus found no threat or warning messages or sounds came up at all.
I managed to remove the threats by using Superantispyware and Malwarebytes to remove the threats.

I am using avast free 5.0.507, I have Avast set on the following:
Heuristics Sensitivity High, Test whole files and Scan for potentially unwanted programs all these are check (tick) in their boxes.
I have all packers checked (ticked) I have this on all the shields except for the last two.

What should I do bout this small problem I have? I have been using Avast Free Antivirus for some years now and it has protected and served me well.
I have noticed that Avast is making my computer freeze as well and the only way I can unfreeze it is by turning my computer off and restarting it which is really FRUSTRATING especially when in the middle of something.

PLEASE HELP: Thanks in advance.

happy avast user :slight_smile:

Using Vista with only 1GB RAM with an AMD SEMPRON ™ PROCESSOR 3500+ 1,80 GHZ must be the problem.

Add 1GB RAM and you will notice a big boost in system performance and reliability.

Use Crucial System Scanner tool to find what RAM the system needs then go to a local PC store to buy the RAM:
http://www.crucial.com

and i would trust and use avast default settings