1) Start > Run > Type CMD.
2)Type "ping 126.96.36.199 -t"
Example of Unstable ping.
A)If you see a lot of "Request timed out", it means your internet is having a problem (connecting to our server that is). Call your internet provider for assistance.
B)You can check why you are lagging too by checking the "ms" if it's unstable like low to high and high to low. It needs to be stable.
Based on my observation only:
1 MS = 1 Ping
10-100 MS = 10-100 Ping In game ( Green = Very Good )
100-300 Ms = 100-300 Ping In game. ( Yellow / Orange = Playable, Little Lag, Delay )
300-500 MS = 300-500 Ping In game. ( Red = RED ALERT RED ALERT Worse XD )