When you right-click any object on a Windows system, there is the option Send to which is able to literally send objects to other computers by automatically opening a new mail and attaching the chosen file as attachment, process them with other programs selectable from a list, or just moving the file to a different location (hold the Shift key when right-clicking to enable more options to Send to). The common user however does not use this function really often, in fact, he may also find it annoying since it might cause short freezes on slower computers if one accidently hovers the mouse over it and thus makes it load a list of applications. But as for every other problem on your computer there is also a solution for this one, disabling the Send to command with the registry.
To do that, open your registry by entering regedit in to a Run... prompt and direct it to the HKEY_CLASSES_ROOT\AllFilesystemObjects\shellex\ContextMenuHandlers\Send To key.
Now the default value that is found in that key is
If you ever want to revert your setting the easiest way is to just save this value somewhere safe, since the thing you need to do to disable the Send to command is to double-click the value and remove the string so that it is empty. Leave the registry afterwards and the command should no longer appear on right-clicking.