Force delete files with a rather large name

Use the Microsoft tool robocopy.exe.

1. Create a new empty folder, e.g. c:\empty

2. Then copy that empty folder onto the folder which contains the long filenames which you're trying to delete, e.g. c:\myannoyingfolder. Do this like so in the command prompt:

   robocopy /MIR c:\empty c:\myannoyingfolder

okay, let's say you want to delete a tree D:\very\long\path, you don't necessarily need to use any tools such as Robocopy.

1. Go to the root directory of the drive which contains the directory which you can't delete
2. Create a directory with a single letter name, eg D:\a
3. Navigate to inside the directory that you want to delete, in this case D:\very\long\path
4. Select all (Ctrl+A) and Cut (Ctrl-X)
5. Navigate to the folder you just created
6. Paste (Ctrl-V)
7. Now, move up to the root directory and delete the temp folder, in this case D:\a
8. Then go back and delete the original directory

You can integrate this functionality into the windows shell. My enhancement to Flo's answer was too long for a comment.

I added a Delete command to the Windows context menu.

The delete.reg file adds registry entries to associate folders with the robodelete.bat batch file.

delete.reg

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Directory\shell\Delete]

[HKEY_CLASSES_ROOT\Directory\shell\Delete\command]
"Extended"=""
@="\"D:\\Documents\\robodelete.bat\" \"%1\""

robodelete.bat

mkdir c:\empty
robocopy /MIR c:\empty %1
rmdir %1
rmdir c:\empty

Note: You may need to change the paths in both files as per your preferences.

WARNING: There is no way to undo this command. It does not use the recycle bin and does not ask Y/N to confirm before destroying the folder for good!