To access the HOSTS file browse to this location in Windows Explorer:
For Windows XP: C:\WINDOWS\SYSTEM32\DRIVERS\ETC
For Windows 2K: C:\WINNT\SYSTEM32\DRIVERS\ETC
For Win 98\ME : C:\WINDOWS
You can look at the HOSTS file in Notepad and see if the website you were trying to visit is listed. If so, erase that entry (you may want to erase the whole file if a program loaded a bogus HOSTS file) and save it in Notepad. You should then be able to view the website.
*This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Comcast or any of its affiliates.