Make sure that XAMPP components and other activities are stopped and uninstalled as a service including the Control Panel before uninstalling XAMPP?
Now You can delete xampp folder
Don’t try reinstall xampp over the top of an already installed xampp or you will have issues.
Make sure apache is stopped and un-tick the Svc box if ticked then close the Control Panel.
Go to .\xampp\apache and double click on apache_uninstallservice_2.2.bat

open your Control Panel
Start Apache but don’t tick the Svc box unless you really want Apache to start every time you boot your PC.
IF this doesn’t work
Check the path of the xampp folder if you have older version installed in it before.Like for example you might have older version c:\programme\xampp 1.5.5\ now you have the latest version of xampp installed in c:\programme\xampp\ which windows is not able to find the path of the service, as it was linked to the old directory.
