Find in Files: Search all code in Team Foundation Server

Team Foundation Server 2015 (on-premises) and Visual Studio Team Services (cloud version) include built-in support for searching across all your code and work items.

You can do simple string searches like foo, boolean operations like foo OR bar or more complex language-specific things like class:WebRequest

You can read more about it here: https://www.visualstudio.com/en-us/docs/search/overview

There is another alternative solution, that seems to be more attractive.

1. Setup a search server - could be any windows machine/server
2. Setup a TFS notification service* (Bissubscribe) to get, delete, update files everytime a checkin happens. So this is a web service that acts like a listener on the TFS server, and updates/syncs the files and folders on the Search server. - this will dramatically improve the accuracy (live search), and avoid the one-time load of making periodic gets
3. Setup an indexing service/windows indexed search on the Search server for the root folder
4. Expose a web service to return search results

Now with all the above setup, you have a few options for the client:

1. Setup a web page to call the search service and format the results to show on the webpage - you can also integrate this webpage inside visual studio (through a macro or a add-in)
2. Create a windows client interface(winforms/wpf) to call the search service and format the results and show them on the UI - you can also integrate this client tool inside visual studio via VSPackages or add-in

Update: I did go this route, and it has been working nicely. Just wanted to add to this.

Reference links:

1. Use this tool instead of bissubscribe.exe
2. Handling TFS events
3. Team System Notifications

Another solution is to use "ctrl+shift+F". You can change the search location to a local directory rather than a solution or project. This will just take the place of the desktop search and you'll still need to get the latest code, but it will allow you to remain within Visual Studio to do your searching.