mythxpak.exe

I have a mythxpak.exe file that can't be removed.  It says that it stems from the age of empires game.  I am pretty sure it is a virus because it is blocking me from getting to certain websites, including signing into my comcast e-mail address.  If I scan the PC with Norton it comes up clean but when I restart the computer the scan pops up that there is an infected file that can't be quarantined. 

 

when I to the Norton security page and click the pull down get support it says that I cannot connect to the internet.  I also can't sign into certain websites 

 

I am currently running windows XP

Service Pack 3