Mysql5.2.20 start service and apply security settings

Mysql5.2.20 start service and apply security settings error solution: 1. uninstall MySQL. 2. type regedit in "run" to enter the registry. 3. Delete the HEKY_LOCAL_MACHINE \ SOFTWARE \ MYSQL directory 4. Delete the HKEY_LOCAL_MACHINE \ SYSTEM \ ControlSet001 \ Services \ Eventlog \ Application \ MySQL directory 5. Delete the HKEY_LOCAL_MACHINE \ SYSTEM \ ControlSet002 \ Services \ Eventlog \ Application \ mySQL directory deletion 6. HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ Eventlog \ Application \ MySQL directory deletion 7. Delete the installation directory C: \ Documents and Settings \ All Users \ Application Data \ MySQL folder 8. Delete the folder under the MySQL installation path. 9. Go to the Registry and use F3 to search" MYSQL "keyword, and then delete all files and folders related to MYSQL that can be deleted. 10. You can install it again.