Can't search from address bar

[jend]

Although I could do it in the past, I can no longer search from my address bar. I get the Page Cannot Be Found message and it is driving me crazy. I've looked in all the "usual places" for solutions, but can't find any. I saw where someone else posted here about this issue in the past and was told to look for "hosts" files. I do see them here. Do I need to delete these? How did they get here - by running ad-aware or installing the Google toolbar (which I have subsequently uninstalled since I thought that that may have been my problem). Thanks.