folders are not created from java idea via mkdir ()

I create folders in the environment with a relative path:

String pathDest = "Projects/AllJava"; File dir=new File(pathDest); dir.mkdirs(); 

it's okay But if I use the full path:

 String pathDest = "С:/Aux/All"; File dir=new File(pathDest); dir.mkdirs(); 

folders are not created anywhere. Interestingly, if I use a verification block

 if(!dir.exists()){ dir.mkdirs(); System.out.println("Directory created."); } 

the code is included in the block and a corresponding message is issued to the console, and folders are not created ?! Help me please!