Help Installing Xvid Codec?

[Jessins]

I recently got a new laptop installed with Windows 7 64 bit. I've been successful in installing other codecs and freeware, but when I try to install Xvid the file gets deleted before installing. The computer claims it doesn't have a valid digital signature so it's "unsafe". I know that the antivirus programs I installed aren't deleting it because I've already tried disabling them, but I also can't find anything in Windows or IE's security settings that would delete the file. Does anyone know how to solve this problem? Is there some program or setting I have to disable to install it?

[soupfine]

Get the codec from a reliable source or the developer:

http://www.xvid.org/Downloads.15.0.html