Here’s a step by step guide to delete team project from TFS, Team Foundation Server Service.
1. Open “Developer Command Prompt” under “Program Files>Microsoft Visual Studio” or in Windows 8 type “Developer“.


2. In the command prompt, use this command template below to delete your project from TFS. Replace the YourTFSName to yours and also the ProjectName to the name of your project.
TfsDeleteProject /collection:https://<strong>YourTFSName</strong>.visualstudio.com/DefaultCollection <strong>ProjectName</strong>

3. Hit “Enter” and then “Y” if you are prompted for confirmation.

4. Done. Double check by login to your TFS online.