Deleting an Undeletable, Currently In-Use Files/Folder in Windows

Problems :
- It may be fully Empty(null size).
- 'File/Folder in use' error.
- Can't delete a file/folder (insert cryptic reason).
- Rebooting doesn't help delete the file.

Open command prompt in windows (run 'cmd' ).

Go to the directory where undeletable file/folder is.

Now, close the explorer.exe process from the task manager.

Enter rd "folder name" for directory & del "file name" for file.

Now your undeletable folder/file is deleted.