That would be because the HOSTS file is along the lines of the registry. Unless you really know what you're doing, you're best off just leaving it alone. Of course if you know what you're doing, you tend to leave them alone anyway.
If the OP, or anyone else, modified the HOSTS file, then each and every time there's some kind of an issue connecting to any website, will need to check that first. So what happens if 3-6 months from now, the OP forgets they ever even modified the HOSTS file, and is trying to get to some site blocked by it? Or maybe some website uses a script function that is hosted on some website blocked by that file. They could spend hours, days, weeks, who knows how long trying to trace down some kind of browser or malware issue that doesn't exist, and we wouldn't be able to help them because they wouldn't think to tell us they had a modified HOSTS file. It's pretty easy to see someone writing it off as damage to the OS if any malware were ever to be found on the system, and when Internet Explorer is involved, that's practically a given. All the while, the solution is really simple, but the OP doesn't know enough to mention it, or doesn't even remember doing it.
The HOSTS file on Windows is just a remnant from Microsoft porting the FreeBSD TCP/IP stack to form the basis of Winsock anyway. There's a reason they buried it deep inside the Windows subdirectory where most people would never think to go looking. Same reason they never provided any sort of GUI front end to it, making it easy to add/remove domains. Some people just need to learn how to take a hint.