Most people would be happy with ads not showing, I suppose, but - of course - there are exceptions.
I've got some news for you: it isn't a gif. It's a flash. And if you move your mouse over it, it moves: not the car (a saturn sky red line) but a light moves over it. Wow.
Go to www.macromedia.com and download their flashplayer. It comes standard with IE, but maybe something has gone wrong. If you installed some flash-blocker (makes sense when on dial-up) you should disable that.
It might be also that the flash file is on some site that's blocked by an adblocker or in your hosts file. As long as it doesn't play you should be able to see the full url (to check that) by a right click>properties.
By the way, why do you state so explicitely it's a gif, when it's easy to see it isn't (on both of your PC's, in fact). With the wrong question you're likely to get the wrong answer. In this case, it was a great help that you give a link, or nobody would have come up with flash if you talk about gif.
I amusing WIN XP Media Edition & IE 6.0.
Here's an example -
When I open yahoo.com there always a banner/ad of some sort on the right side - today it's a Saturn.com ad. All I see is the red x.
I have checked that my internet options to show pictures is checked. I have verified the my encoding is correct.
Does anyone have another idea? This is driving me nuts. I have 2 PC's in the house & the other older one is fine. I have tried to do a comparion of everything under Options, advanced and they are identical - with one excpetion - Microsoft VM isn't listed on the new one using Media Edition. One the old one it has JIT complier for virtual machine enabled (requires restart) checked. I have no clue what that is or what it does.