Instructions
Use Steam's server browser to filter servers by geographical location and connect to servers that are close to you. To open Steam's server browser, right-click on the Steam icon in the notification area of the Windows taskbar and select "Servers." Click on "Change Filters" and select your geographical area from the "Location" drop-down menu.
Shut down running applications before launching "Counter-Strike: Source." Some applications, such as peer-to-peer programs or download managers, can use part of your Internet bandwidth while you are playing "Counter-Strike: Source," which can cause increased latency.
Upgrade your Internet connection. "Counter-Strike: Source" requires a fast Internet connection for optimum performance. Contact your local Internet service provider for details about the connection options available in your area.