The English language forums are here (this may well be moved there by a forum moderator
Do a forum search for access violation
in the XAMPP for
Windows forum and it will reveal the answers you want as this question has been asked many times.
It has been installed as a service and needs the service uninstalled.
Right click on the traffic light icon select Win NT>
and the controls are there to install and uninstall the service and to Shut down the tool.
The error messages can be stopped by right click on the Task Bar>Task Manager>Processes tab and find the winmysqladmin file, highlight and click End Process.