No Applications Detecting Internet Connection

ok so, a couple nights ago we were having trouble with our McAfee software and were told to redownload the software, but in order to download the software we needed to replace the Host File, the McAfee online assistant sent us the file and all we had to do was paste it, and click yes to "replace"
we then continued to download the software. however, upon restarting the computer no application except for internet explorer would detect that i am indeed, connected to the internet. I dont know if i posted this in the right place but i just took a guess. if it matter we have wireless internet and im running Windows XP SP2. I'm somewhat familiar with computers but this has me stumped...help is very much appreciated.

 

thanks, we got as far as being told to restart the computer when we did, McAfee was no longer installed. and im saying nothing works. i usually work with Firefox. it wont connect, nor will MSN, or uTorrent or any type of download

 

its another host file thats all i replaced it with. im guessing it was an update or something but its so much so that nothing else is detecting it. if i answered wrong please clarify and ill do what i can