Personally, i have never used avast, though, if it does some firewall, i might have blocked ur program from going to internet if it accesses internet..
otherwise, i don't see how those three program might affect your computer...
lisp hacker :D
running: FreeBSD 5.4 - still learning :D
develop with: SBCL + emacs for lisp, Anjuta IDE +gcc for c, SPE for python..
browse with: opera