Reopen the Run dialog ( Windows Key + R ), type %LOCALAPPDATA% , and delete the and Blizzard folders there as well.
To resolve the "Preparing Game Data Link" error, follow these troubleshooting steps: starcraft 2 preparing game data link
If you are looking for a to fix this issue, or simply need to understand why this message appears every time you launch the game, this guide will walk you through the causes and solutions to get you back into the Koprulu Sector. What is "Preparing Game Data"? Reopen the Run dialog ( Windows Key +