how to join computer to domain through powershell

Question

I have just done a fresh installation of windows 7 professional, and I would like to join my pc to domain through powershell but getting some error here is the code which I am using

Add-Computer -ComputerName HMD-PC002 -DomainName mydomain -Credential     
mydomain\Administrator

Add-Computer : Computer 'HMD-PC002' failed to join domain 'mydomain' from its current  
workgroup 'WORKGROUP' with
following error message: Unknown error (0xa8b).
At C:\Users\HMDPC002\Desktop\add-pc_to_Domain.ps1:8 char:1
+ Add-Computer -ComputerName HMD-PC002 -DomainName mydomain -Credential mydomain\A ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : OperationStopped: (HMD-PC002:String) [Add-Computer],   
InvalidOperationException
+ FullyQualifiedErrorId :   
FailToJoinDomainFromWorkgroup,Microsoft.PowerShell.Commands.AddComputerComma

Answer 1

There was an easy solution to this, i didnt configure my dns server i had to change it manually and after populating the two field i ran the following script and it worked

Add-Computer -DomainName mydomain -Credential mydomain\Administrator -Restart

However i want powershell to change the dns setting i will ask this in a separate question

Answer 2

What i did before joining a server to domain:

1) Check the connectivity between DC and Server. Ping the domain controller. It should ping if both are on same subnet, else domain can't be joined.

2) Ran this powershell command:

PS C:\Windows\system32> add-computer domain.com -Credential domain\administrator WARNING: The changes will take effect after you restart the computer SERVERNAME.