WIN 7 Network ID option is greyed out | can't join a domain

[userl]

Question
Network ID tab is greyed out in My Computer> Properties> Computer Name. ?
Am trying to join a domian to my personal laptop (WIN 7) but the Network ID option is greyed out and am unable to proceed .

1.
In the Network Connection properties, make sure you have Client for
Microsoft Networks installed.

Then make sure the Workstation service is enabled and running
(Start-->Run--> SERVICES.MSC) It should be set to auto. Stopping this
service will make the Network ID box be greyed out.

You'll probably also want to make sure you have File and Print Sharing
installed, and the Server service running as well.

---

2.

Connect your computer to a domain

A domain is a collection of computers on a network with common rules and procedures that are administered as a unit. Each domain has a unique name. Typically, domains are used for workplace networks. To connect your computer to a domain, you'll need to know the name of the domain and have a valid user account on the domain.

1. 
   
   Open System by clicking the
   Start button , right-clicking
   Computer, and then clicking
   Properties.
2. 
   Under
   Computer name, domain, and workgroup settings, click
   Change settings.
   If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
3. 
   Click the
   Computer Name tab, and then click
   Change. Alternatively, click
   Network ID to use the Join a Domain or Workgroup wizard to automate the process of connecting to a domain and creating a domain user account on your computer.
4. 
   Under
   Member of, click
   Domain.
   
   
   The Computer Name/Domain Changes dialog box
5. 
   Type the name of the domain that you want to join, and then click
   OK.
   You will be asked to type your user name and password for the domain.
   Once you are successfully joined to the domain, you will be prompted to restart your computer. You must restart your computer before the changes take effect.