Problem with Avast Free

I have a problem since a while with Avast Free edition. Many times the active window where I workin in, gets inactive for 1-2 seconds. When I have copy something at the same time (with CTRL+C) and I paste it, then I get the following in stead of the text I copied:

[Window Title] avast! NG command-line tool

[Main Instruction]
avast! NG command-line tool werkt niet meer

[Content]
Er wordt naar een oplossing voor het probleem gezocht…

[Annuleren]

Looks like Avast try to do something on the background, but that process crashes.

Is there a solution for this problem?

Disable/remove the NG component.