Solution:

Open command prompt as Administrator. Execute the follwoing commands

1. %windir%\system32\inetsrv\appcmd recycle apppool /apppool.name:"Microsoft Team Foundation Server Application Pool" 
2. net stop tfsjobagent 
3. net start tfsjobagent

Exception:

Solution:

1. Open Command Prompt Window as Administrator (Right click on CMD shortcut) 

2. Execute the follwoing command

Regsvr32 “C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE\PrivateAssemblies\TFSOfficeAdd-in.dll”

Solution:

Execute the following command:

TFSSecurity.exe /g+ "Team Foundation Service Accounts" n:"[Domain]\[User Id]" /server:http://tfs:8080/tfs

Command: systeminfo.exe

Displays detailed configuration information about a computer and its operating system, including operating system configuration, security information, product ID, and hardware properties, such as RAM, disk space, and network cards.

Syntax
systeminfo[.exe] [/s Computer [/u Domain\User [/p Password]]] [/fo {TABLE|LIST|CSV}] [/nh]

Parameters
/s Computer : Specifies the name or IP address of a remote computer (do not use backslashes). The default is the local computer.
/u Domain\User : Runs the command with the account permissions of the user specified by User or Domain\User. The default is the permissions of the current logged on user on the computer issuing the command.
/p Password : Specifies the password of the user account that is specified in the /u parameter.
/fo {TABLE|LIST|CSV} : Specifies the format to use for the output. Valid values are TABLE, LIST, and CSV. The default format for output is LIST.
/nh : Suppresses column headers in the output. Valid when the /fo parameter is set to TABLE or CSV.
/?: Displays help at the command prompt.

Sample output

systeminfo.exe

Host Name:                 XAVIER
OS Name:                   Microsoft Windows Server 2008 R2 Standard
OS Version:                6.1.7601 Service Pack 1 Build 7601
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Member Server
OS Build Type:             Multiprocessor Free
Registered Owner:          Infrastructure Server
Registered Organization:   Halliburton
Product ID:                00477-001-0000421-84103
Original Install Date:     12/20/2012, 10:09:54 AM
System Boot Time:          6/20/2013, 10:02:31 PM
System Manufacturer:       VMware, Inc.
System Model:              VMware Virtual Platform
System Type:               x64-based PC
Processor(s):              4 Processor(s) Installed.
                           [01]: Intel64 Family 6 Model 44 Stepping 2 GenuineIntel ~3465 Mhz
                           [02]: Intel64 Family 6 Model 44 Stepping 2 GenuineIntel ~3465 Mhz
                           [03]: Intel64 Family 6 Model 44 Stepping 2 GenuineIntel ~3465 Mhz
                           [04]: Intel64 Family 6 Model 44 Stepping 2 GenuineIntel ~3465 Mhz
BIOS Version:              Technologies LTD 6.00, 4/15/2011
Windows Directory:         C:\Windows
System Directory:          C:\Windows\system32
Boot Device:               \Device\HarddiskVolume1
System Locale:             en-us;English (United States)
Input Locale:              en-us;English (United States)
Time Zone:                 (UTC-06:00) Central Time (US & Canada)
Total Physical Memory:     16,384 MB
Available Physical Memory: 14,725 MB
Virtual Memory: Max Size:  22,526 MB
Virtual Memory: Available: 20,750 MB
Virtual Memory: In Use:    1,776 MB
Page File Location(s):     C:\pagefile.sys
Domain:                    Xavier.com
Logon Server:              \\Xavier
Hotfix(s):                 2 Hotfix(s) Installed.
                           [01]: KB981391
                           [02]: KB981392
Network Card(s):           1 NIC(s) Installed.
                           [01]: Intel(R) PRO/1000 MT Network Connection
                                 Connection Name: Public
                                 DHCP Enabled:    No
                                 IP address(es)
                                 [01]: 00.00.000.000

Explanation

VS cache the login credentials for workspace. When we try login with current credentials still it take old credentials from cache

Solution

clear the cache and reload it. Follow below steps to do that:
Step 1: Open VS command prompt.
Step 2: Run below command to clear the local cache.

tf workspaces /remove:*

Step 3: Run below command to set the Owner for respective TFS server

tf workspaces /s:TFS_ServerName

For Windows XP, delete all the contents under:
 C:\Documents and Settings\[USER]\Local Settings\Application Data\Microsoft\Team Foundation\
For Windows 7, delete all content under:
 C:\Users\[User]\AppData\Local\Microsoft\Team Foundation\