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 disconnections in StarCraft: Remastered
Troubleshooting steps for disconnection issues in Warcraft III.
Troubleshooting steps for performance-related problems.
How to obtain error logs for Blizzard games
Information about this error when login to Classic Warcraft III
Information about troubleshooting problems with the Blizzard Battle.net friends list
How to disable the Xbox DVR in Windows 10 Anniversary
Information on what to do when a game update is stuck at 0 B/Ss
How to install a Blizzard game you already own on a different computer