To put a long story short, about a few weeks ago I started getting these horrible lag spikes every 30 seconds or so when playing games such as League of Legends, when I would lag up in-game, I'd check what my PING was using the in-game indicator, and it was going as high as 600ms, whereas usually I'm playing on around about 24.
I then went and researched some tests, didn't seem to help though.
The first test I did was opening up the Windows (Im running on Windows 7) cmd, and entering in "Ping Google.com -t". This would then send me my ping every second or so, it's usually around 22ms, but occasionally shoots up high to 1800's.
I then went back onto cmd, and did the same kind of test, however replacing "google.com" with my own IP address. This came back as a solid 1ms all the time, with no changes at all.
I'm not too sure what the problem is to be honest, as it doesn't seem to be affecting my other devices such as my PS3 or phone, and it only seems to be affecting my games such as Counter Strike, SMITE and League of Legends, which, typically, is where you need smooth running internet.
We haven't bought a new router or changed anything with our devices or internet a few weeks ago which would have affected this, so it's not like something is now screwing with the internet.
I'm currently using WiFi to connect to my computer, and I am UNABLE to connect it to an Ethernet cable as the router is downstairs, whereas my computer is upstairs.
Not sure if it helps, but the household's ISP is SKY Internet.
Thanks for the help!