If you are looking how to remove invalid files from your system, you will need to run the del /s command:

 del /s "\\?\<File path>"

This command deletes specified files from the disk. Keep in mind that deleting files from the Windows command line does not send files to the Recycle Bin, that means that the file will be lost. However as it's invalid you shouldn't be worried about it. For example, to delete a file that can't be deleted manually with the name helloworld. and located in the path E:\Our Code World\Workspace, you could use the following command to remove it:

 REM Delete the helloworld. file !
 del /s "\\?\E:\Our Code World\Workspace\helloworld."