If you auto-dial with IE5.x and have SP5 or SP6 applied to your Windows NT 4.0 installation, you will likely encounter:
The page cannot be displayed
Cannot find server or DNS error.
The workaround is to either:
1. Dial your ISP, before starting IE 5.x.
2. Quit IE 5.x and restart it after it connects.
3. Implement tip 0090.
Microsoft is aware of the problem.