WC3 lag woes

Well, I'm not sure where to start, but here goes:

As of late, whenever I play Warcraft 3, I start have frequent lag spikes. This started happening about a month or two ago, I suppose. Before then I almost never lagged. But now I lag in every game I do, without fail. Yet it's only in WC3 that I lag; if I'm playing some other game (i.e., Diablo 2), there's no lag. And if I'm on Ventrilo while playing WC3, vent never lags, even when I'm lagging in WC3. Likewise, surfing is virtually lag-free. I tried defragging and running adaware last week, and that made the lag spikes less frequent, but still there. Finally, just today I tried reinstalling WC3 (I deleted the folder and everything); yet now the lag seems to be even worse. I end up dropping from the lag 5 minutes into every game. I'm not sure what the problem really is, or why it solely affects WC3.

Sorry if I'm rambling, I'm just trying to provide details.

P.S. - I'm not particularly computer savvy, so please bear with me

 

Provide your net connection details please. When is the last time you checked for malware?