Horrid lag in game and out

Right, both me and my sister tend to play a lot of games using steam.
When both of us play, there is just a whole lag fest for the both of
us. This never used to be a problem back on Windows XP, but now seeing
we're both on vista it annoys the **** out of either one of us.

Also when shes playing games and im not, it takes ages to go on sites
and lags more but where as whenever im in a game and she wants to sites
its all fine for her, which really annoys me

I'm running Vista Ultimate x64 and shes on Home Premium x86. Also I
happen to be connected directly to my router and my sisters connected by
wireless using some on-board wireless card. The router is a Netgear
WPN824v2


Anyone know why whenever both of us are playing it lags and why she
happens to ruin my browsing time?


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converge