Sometime you need to some operation on file or folders like rename , delete , move ect … you can get an error “file is use” :
Nice trick is to open “Resource monitor” -> execute from run : resmon.exe (or right click on task bar -> Task manager -> Preformance TAB -> “Open Resource Monitor” at the botton )
On the “Associated Handles” there is a search windows, enter the name of the file or folder and click search, you will get the PID of the handler which holding the file or folder
Good Luck