Internet problems... Help!

After recently attempting to run a few Linux LiveCD’s (Ophcrack/Knoppix, just for fun), I noticed that for some reason, while running those, I could no longer connect to my internet connection (wired). After returning to Windows XP, I figured that would fix my connection problems, and low and behold, the problem still existed. It said that my network cable was unplugged, when it in fact wasn’t. The weird thing though, was when my Linksys WRT-54G wireless router’s “one push easy setup” button started blinking, without me pushing it. After that, I got a notice with WinPatrol that some host file was trying to be changed, but I denied that. After that, I then got the following message, via my firewall, which makes me quite suspicious to this being some sort of attack perhaps:

http://i46.photobucket.com/albums/f118/Mhogan35/Message.jpg

Any ideas? Help would be greatly appreciated, and thanks in advance for any help that I can get. I already have tried to directly connect my modem to my computer, but that didn’t help any. Thanks again for the help…
–Matt

Maybe this recent thread could throw some light to ‘our’ problem…
http://forum.avast.com/index.php?topic=26089.0

Also: http://forum.avast.com/index.php?topic=16436.0