When you are having trouble connecting to a network resource, your local computer will often cache the error condition in one or more places. Common troubleshooting steps to resolve cached error conditions include clearing your NetBIOS and host name caches. Also, if you are using Internet Explorer to access a site, you may need to clear that cache as well. To clear the host name resolver cache (sometimes called the DNS name cache) as well as the NetBIOS name cache (sometimes called the computer name cache), open a Command Prompt window. Starting with Windows Vista, you may need to open an elevated Command Prompt.
  1. To open a Command Prompt. Click Start, click Programs or All Programs, click Accessories, and then click Command Prompt. To open an elevated Command Prompt perform those same steps, except instead of clicking Command Prompt, right-click Command Prompt and select Run as administrator.
  2. Enter the following commands, pressing the ENTER key after each line:

ipconfig /flushdns

nbtstat –R

To clear the Internet Explorer 8 cache:
  1. In Internet Explorer 8, click Tools and then click Internet Options.
  2. Click Delete and then ensure Temporary Internet Files is selected.
  3. Click Delete and then click OK.