If you receive the following in the Application event log:
Event ID: 1000 Event Source: Userenv Description: Windows cannot determine the user or computer name. Return value (1722),your preferred DNS server address on this client may be unreachable.
NOTE: This may result in a very long logon time.
To correct the problem:
1. Right-click My Network Places and press Properties.
2. Right-click Local Area Connection and press Properties.
3. Press Internet Protocol (TCP/IP) and press Properties.
4. In the Preferred DNS server box, type the correct DNS server address.