If enabled Search and Indexing Options in Control Panel does not allow opening the Modify Locations dialog. Otherwise it can be opened. Disabled by default.
Policy path:
Windows Components\Search
Scope:
User
Supported on:
Any version of Microsoft Windows with Windows Search 4.0 or later
Registry settings:
HKCU\SOFTWARE\Policies\Microsoft\Windows\Windows Search!PreventModifyingIndexedLocations
Filename:
Search.admx