Delete an “Undeletable” File / Folder

You all Are familier With such kinfd of ERROR in windows so how to Fix them.
Step 1:- Open a Command Prompt window and leave it open.
Step 2- Close all open programs.
Step 3:- Click Start, Run and enter TASKMGR.EXE
Step 4:- Go to the Processes tab and End Process on Explorer.exe.
Step 5:- Leave Task Manager open.
Step 6:- Go back to the Command Prompt window and change to the directory the AVI (or other undeletable file) is
located in.
Step 7:- At the command prompt type DEL <filename> where <filename> is the file you wish to delete.
Step 8:- Go back to Task Manager, click File, New Task and enter EXPLORER.EXE to restart the GUI shell.
Step 9:- Close Task Manager.
Or you can try this
Step 1:- Open Notepad.exe
Step 2:-Click File>Save As..>
Step 3:-locate the folder where ur undeletable file is
Step 4:-Choose 'All files' from the file type box
Step 5:-click once on the file u wanna delete so its name appears in the 'filename' box
Step 6:-put a " at the start and end of the filename
(the filename should have the extension of the undeletable file so it will overwrite it)
Step 7:-click save,