Two computers, same router, one lags, other doesn't

[Rufi]

Hello.
We have one router and we plugged a second computer in. We first played Battlefield 3 and both had fine pings. Later, the original computer, which had always used this router was fine, BUT. The other computer began (I guess) to have problems. Diablo 3 and League of Legends had almost unplayable pings (well, around 200). In the meanwhile the other computer was playing BF3 with good pings.
Any suggestions?

 

[g0rd0]

Well, some system specs would be helpful as would some info about your router. Generally, the question is too general to be answered.