In this case, you can reboot your computer and try to open Bluestacks again. If the problem persists, it's advised to perform a fresh installation of the program. To do this, first you need to uninstall the application by going to Start > Control Panel > Programs and features, select Bluestacks and press Uninstall. After you did this, use the Download button from application's review page to obtain a link for the latest version. Also, an update of the Net Framework service could help. After you completed all the mentioned steps, your Bluestacks should work.