One day, you're surfing the Internet just fine. The next day, some or all of the sites you typically visit are no longer accessible. Troubleshooting "Page cannot be displayed" or "Cannot find server" error messages can be frustrating. There are a number of possible causes and it may take a bit of digging to get to the root of the problem. Here's how to troubleshoot some of the more common Internet connectivity problems.
Weed out the obvious
Before you begin searching for stripes on a horse to call it a zebra, check to make sure it isn't really just a horse. Take a deep breath, step back, and check the obvious. Don't skip this step - in most cases, the cause is much more benign than we might think.
To assist with hardware troubleshooting, download Microsoft's Network Diagnostics for Windows XP tool
Check for configuration issues
In many cases, the "Page cannot be displayed" or "Cannot find server" error messages may be a result of a modified HOSTS file, problem with Internet Explorer settings, or an oversized index.dat file.
A corrupt Winsock
Did you install new software, remove software, or update software recently? Did your antivirus or antispyware scanner remove a virus or other malware just prior to the problem occurring? If either of the above are true, the "Page cannot be displayed" or "Cannot find server" error messages may be a result of a corrupt Winsock or missing Licensed Service Provider (LSP).
After using LSP-Fix, reboot the system and attempt to access the Internet. If the problem still persists, follow the instructions outlined in Microsoft KB811259 to determine and recover from Winsock corruption.
Note: the steps outlined in KB811259 are best suited for tech-savvy users. The less tech-inclined may wish to download WinSock XP Fix instead (for Windows XP only). Those using Windows 98/ME may wish to use Winsock2 Fix. While highly regarded by users, neither of these programs offer technical support and both should be used at your own risk.