If it is about user access right, you can change it trough cacls command.
First, of course, Start>Run>type "cmd" to call Dos Window.
If the folder in question is in C:\Program Files\Kerio, then,
cacls "C:\Program Files\Kerio" /e /r /c /g "Your User Name":f
This should grant your account full access to the folder. You can check it with the below command.
cacls "C:\Program Files\Kerio"
Of course, you can do the above in Safe Mode and try to remove the folder with rd command just for better bet. However, I am not sure if it works since you have already tried Safe Mode.
