How to check weather a username exists on a domain comtroller?.

The below code will help you to check wether a specified user exists on the domain controlller or not.


bool AdsVlaid = false;

string username = "it";

string domain="server";

string path = String.Format("WinNT://{0}/{1},user", domain, username);

try

{

DirectoryEntry.Exists(path);

AdsVlaid= true;

}

catch (Exception ex)

{

AdsVlaid = false;

MessageBox.Show(ex.Message);

// For WinNT provider DirectoryEntry.Exists throws an exception

// instead of returning false so we need to trap it.

}

For more infomation please visit the below links

http://www.codeproject.com/KB/system/everythingInAD.aspx

http://stackoverflow.com/questions/1329833/how-to-check-if-windows-user-account-name-exists-in-domain