Internet ping problem?

[Jaron]

My brother and I have been using the same internet to play League of Legends together for many months now, and have even had up to 5 people using our internet at the same time, with little effect on my in-game ping whatsoever.

I have just had a computer built for me, and it's crazy fast. Everything about it is mint, and top of the market. I got a Gigabyte GC-WB867D-I wireless card so that I could use my internet from my bedroom, which is connected to the living room where the modem is. When I use this computer to play LoL, I run on a solid 400 frames per second easily, but my ping spikes from 40ish to upwards of 1000 ping frequently. I have maximum reception in my room, and I have had my brother play while sitting next to me. I have tried it on all other computers in the house and only my computer is having problems.

As far as I know, all drivers are up to date, and I have even tried reinstalling them to no avail.

Thanks in advance for the help.