only one program has internet connection

i think theirs something wrong with my internet connection or theres a virus on my computer one of the two but ill try here first. i can only connect to the internet with Firefox, every time i try to sign in on msn or use internet explorer they say they cant connect and worst i cant get my anti-virus or anti-spyware to connect to download new definitions. i checked my firewall and it says it aint blocking the connection and i know im connected to the internet. the only other help i can give is when i diagnose the connection for internet explorer it says the something wrong with the proxy settings so some advise on that would be nice but does the proxy setting on internet explorer really effect my anti-virus and stuff, there are 2 other things that dont connect but i dont see how they work with internet explorer. and thats it, any help would be really nice

 

Have you tried a system restore or even try booting in "safe mode with networking" first to see if it is still happening, also try emptying your cache !

Rusty

 

well it still doesnt work in safe mode and i didnt want to use system restore but i guess i had no choice. so i used system restore and it works fine now but i would still like to know what the main problem was so i can try to avoid it in the future but i do know how hard it is trying to figure out a computer problem with little to go on but like i said it works and im happy