This Windows NT / Windows 2000 registry hack will remove run from the Start Menu and it will also prevent users from launching the Run dialog via pressing the Windows Key + R.

Hive: HKEY_CURRENT_USER
Key: Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
Name: NoRun
Type: REG_DWORD
Value: 1

Desktop and Explorer Restrictions Tips:

Desktop icons hidden
File menu in Explorer is removed
Map Network Drive and Disconnect Network Drive menu from Explorer removed
Network Neighborhood icon removed and prevent network access from Explorer
Common Groups from Start Menu removed
Find command removed from Start Menu
Run command removed from Start Menu
Shut Down button removed from Start Menu
Control Panel, Printers and My Computer in Explorer hidden and on Start Menu
Taskbar on the Start Menu hidden
Most Recently Used entries removed from Run history
Menus do not display upon right click on Taskbar, Start Button, Clock, or Taskbar icons
Menus do not display upon right-click of Desktop or Explorer's Results pane.
Only programs in Restrict subkey can be run
Remove Run command from Start menu