Explanation
The reason is that the build agent account doesn't have permission on your source tree to checkin other user's changes

Solution
You need to right click on the source tee in Source Control Explorer. Then click Properties and go to Security tab. You can then select the corresponding user of group and check the Allow checkbox for Check in other user’s changes.

Explanation:

The default value of work item attachments is 4KB.  Attachment size can be adjusted up to 2GB.

Solution:

Log in as TFS Admin on the TFS Application tier and use the following web services to increase the attachment size.

http://localhost:8080/tfs/<Collection Name>/WorkItemTracking/v1.0/ConfigurationSettingsService.asmx

Exception:

A backup plan already exists for this TFS system on a different machine

Explanation:

The database has an extended property that it stores the name of the machine used for the backups. This was set while running on the original box. You need to remove this value before the power tool will allow you to configure a new backup.

Solution:

Execute the stored procedure on Tfs_Configuration DB

EXEC sp_dropextendedproperty @name = 'TFS_BACKUP_PLAN_CONTROLLER'

Solution

http://support.microsoft.com/kb/2608743

Group Name: TeamTestAgentService

This group contains the minimal permissions needed for a test agent to connect to a test controller.Connect to a test controller
Before you configure a test agent, add the user accounts that you will use to run the test agent service. This is the user account that you specify in the Test Agent Configuration Tool when you install a test agent.

Group Name: TeamTestControllerUsers

Includes permissions from the TeamTestAgentService group.Start test runs.View test results
Add users that only need to run tests and view test results.

Group Name: TeamTestControllerAdmins

Includes permissions from the TeamTestControllerUsers and TeamTestAgentService groups.Delete, pause, or postpone any test run.Add, remove, and change the status of test agents.Create lab environments.
Before you configure a test agent, add the user accounts that you will use to run the test agent service. This is the user account that you specify in the Test Agent Configuration Tool when you install a test agent.