Out-of-date drivers and operating systems can cause a variety of issues, and are one of the first things to check when a game is having problems.
Troubleshooting steps for performance-related problems.
Troubleshooting steps for latency problems in StarCraft II
Follow these steps to troubleshoot problems with your low-speed or wireless internet connection.
Troubleshooting for problems installing or patching the Starcraft II game client
Troubleshooting for installation-related problems on Mac.
There's a problem with the connection to the Blizzard servers.
Information about troubleshooting problems with the Blizzard Battle.net friends list
You have attempted to connect to an invalid server. If this problem persists, please contact Customer Support.
Damaged windows system files can cause a variety of issues playing games, and should be repaired to prevent problems.