Usually we are using REG files to add or replace things in registry.

Do you realize that we can delete registry keys and even values by using this interesting trick.

To delete a value:

; This will delete "DeleteMe" string value

[HKEY_LOCAL_MACHINESYSTEM To-Delete]

"DeleteMe"=-

To delete a key:

; This will delete "To-Delete" key

[-HKEY_LOCAL_MACHINESYSTEM To-Delete]

Sources:

http://support.microsoft.com/kb/310516