Vista - World of Warcraft High Latency? help

Hello guys I have problem with my MS/PING playing WoW and im very sure that is something about Vista.

Why? becouse i just bought a new pc and i was playing with a btter ping and i had Win XP.

At first i was playing with high latency. But then a friend of mine told me about some kind of trick with some .Net framework stuff he gave me, and my ping went below 100 after i installed it. Like magic.

Now i have Vista 64 in my new pc, and i just cant believe that im playing at 360+ ping Again.

I have been very carefull downloading only what is necessary, I mean, im not installing every crap i see on the inet. Im running task manager and i cant see anything strange or unusual.

Im playing from the same place, same connection, etc.

Can anyone tell me how can i fix this, or make my ping go down??

Thanks a lot. And sorry for my bad english!