|Make sure you're not downloading anything.|
Sometimes even Windows itself will download updates in "Windows Update", and won't even tell you about it (depending on the settings). So that's something to check.
Anything that could be updating or connected to the internet can higher ping too so best to close any.
Also, if another computer is using your net, or downloading, that could cause you to lag too.
If you're sure it's not that, then it's most likely the server you're connected to.
If you connect to a server that's hosted in your country, you'll get a fairly low ping like 10-50 or so.
If the ping is on the opposite side of the world, you might get around 200+.
And sometimes the server/host is just having a bad internet day, and everyone lags.
So sometimes you can't help it. If possible, try connect to same country servers.