You cannot connect to the Internet after you install any of the following Microsoft updates:
- Internet Explorer 6 Service Pack 1 (SP1)
- Microsoft Windows XP SP1
- The hotfix that is described in the following
- Microsoft Knowledge Base article:
- 312176 Heavy NTLM Authentication Traffic Occurs Between Internet Explorer and the Proxy Server
- The hotfix that is described in the following Microsoft Knowledge Base article:
- 325662 NTLM Authentication Over an SSL Connection Does Not Work in Internet Explorer 6
This problem may occur if you are using a third-party proxy product that uses only basic authentication.
The following file is available for download from the Microsoft Download Center:
Download the Q331906.exe package now
Source: Technet
