Voice Breaking Up/ Incomprehensible

I can't have a voice conversation over windows live messenger or on
ventrilo without getting the most horrendous lag and/ or the sound
breaking up and being pretty much incomprehensible - to me and to those
I am attempting to communicate with. I know it's not my connection as it
is fine on the other PC which has XP, which leads me to believe a
possible Vista issue? I have way more than enough resources to deal with
voice on Windows Live Messenger and even if it is the only thing
running, the issues remain.

If ANYONE can help me fix this I would truly be most grateful, I have
tried everything I can think of.

TYIA,

S x

p.s. I am running Vista Home 32bit & Windows Live Messenger
8.5.1302.1018


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shoogalips