I had the very same problem. One day i just started to have lags (2-3sec more for game to react at my commands) so I did this and I have no lags now.:
To start this process, you have to open your "Register-editor" in Windows. You can do this by pressing "Start" and pick the "Run" option. In here you type "regedit"
This will open up the "Registry-editor". You will have to find your way to this key:
HKEY_LOCAL_MACHINE -> SYSTEM -> CURRENTCONTROLSET -> SERVICES -> TCPIP -> PARAMETERS -> INTERFACES
Then there will be some large hex keys for your actual network adapters. You will need to click on the one that matches your internet adapter [it will show a ton of information containing all your network details, such as your assign DHCP Address and server info].
Once you have identified the correct adapter, you add a new DWORD 32bit named "TcpAckFrequency", and then update its value to 1 by right clicking it.
After this, reboot your PC and log on Aion to find out your new and reduced ping! Share your experience with the rest of us if you've done this neat little trick.
Special Thanks to : TheAionGuy
Its for Aion but it worked for me. 0 lags now.
Few of my clan mates have same problem and it also worked for them.