As likely to uninstall MySQL Connector.NET.6.9.8 (version number) how can unload, and then leads to can't reinstall this one,
Solution:
1, directory on disk C, there is a hidden file - ProgramData, enter C: \ ProgramData \ MySQL \, delete all files and folders inside; (first to display hidden files)
2, into the registry (run - & gt; Enter regedit)
3, Ctrl + F, the input Connector.net X.X.X (according to their own version), to find the relevant documents, and delete, this step, until the registry couldn't find the Connector.net X.X.X;
(the key is the red circle of folder)
4, the Connector.net X.X.X successful unload

Remember to read the right margin out
Reprint: baidu library