When reinstalling MySql on Windows server 2008, the server does some configurations. You might come up with a error just after configuring the "my.ini" file. The installation process hangs. To fix this you sould:
1. Delete the folder "c:\Program Files\MySql"
2. Delete the folder "c:\Program data\MySql" (*hidden folder)
3. Uninstall MySql from "Control Panel -> Uninstall a Program"
4. Run MySql installer.