Adding a DOS cmd prompt to the Windows right click menu

1.
Go to the HKEY_CLASSES_ROOT\Folder\shell node in the registry (note that Folder includes drives and directories).

2.
Create a new key (from the right-click menu), and call it "DOS prompt".

3.
Under that new key, create a sub-key named "command".

4.
Under that new key (i.e under HKEY_CLASSES_ROOT\Folder\shell\DOS prompt\command), edit the (Default) String value and give it the following value: "c:\windows\system32\cmd.exe %1" (or whatever the path to cmd.exe is on your system).

5.
Now, you can open a DOS window by right-clicking on any directory name in the Windows explorer.