Remove TFS Connection From Solution

To completely remove TFS source control binding follow these two steps:

1. Go to your solution's folder, find and delete all files with *.vssscc and *.vspscc extensions.
2. Open your solution's .sln file in Notepad, and find & remove the GlobalSection(TeamFoundationVersionControl) section.

More details on reference Link

If you want to permanently and completely detach the solution from source control, then try the following:

1. Click the 'No' button to avoid connecting to TFS.
2. In the file menu, go to the source control options and clear the bindings. You'll specifically want File - Source Control - Advanced - Change Source Control...
3. Save the solution.

Next time you open the solution you won't be prompted to connect to TFS.