If you want to migrate one or more TFS Project Collections from one TFS server to another follow this procedure. Procedure is very important and if you skip any step your will have the problem. For that reason read and follow this article from beginning.
NOTE: You can’t to migrate Team Project only, you need to migrate whole Collection. With this process you migrate Work Items and Source Control only. In my second blog post I’ll write about how to migrate Reports and SharePoint sites. That is more complicated procedure.
Stop Team Project Collection which you want to migrate.
Open your SQL Server Management Studio and backup database which you want to migrate. Before backup I advice to shrink your database (log and data).
Copy database on to your new TFS server and restore to SQL server.
Open Team Foundation Server Administration Console go to Application Tier >>> Team Project Collections, click to Attach Collection and follow the Wizard.
Your restored database will appear.
Team Project Collection is attached but with warnings about Reporting, SharePoint Products and Lab Management. As I mentioned before, you can’t to migrate Reports and SharePoint site easy.
Migrated Team Project Collection is up and running.
Check your migrated Project/s.