Error Fix:“Internet Explorer cannot display the webpage” or “Server Not Found”

When you are browsing a web page using any web browser such as Internet Explorer or Mozilla Firefox in Windows Vista or in Windows XP, occasionally some error messages will display,says “Internet Explorer cannot display the webpage” or “Server Not Found”.Also when connecting your computer to a remote server, the connection may return an error message says“Host not available”.There are many possible reasons that may cause the above problems in Windows Vista.The major reasons for this issue in Windows Vista will be the network connectivity issue, such as network disconnection, DNS resolving problem, or remote web server issue, which may be cause the network temporarily down. If you have ensured that this network issues is non-existent and no issue exists on your Windows Vista computer or on your ISP network, and have tried various solutions specific to Windows Vista network problems, try the following tweak to fix these issues:

• Open Windows Vista Registry Editor by type in regedit in Start menu Instant Search field and then press Enter key.
• The Windows registry editor will opens and navigate to the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

• Locate and right click on EnablePMTUDiscovery registry value in the right pane of the Windows Vista registry editor, and then select Modify option from the context menu.
• In the opened value data text field, change the value 0 and enter 1 as its new value, then click OK button.
• Exit Windows Vista registry editor and restart your computer.

Enabling the Windows Vista registry key of EnablePMTUDiscovery instructs the TCP/IP to try to automatically detect the MTU for all connected networks along the path to a remote host, which may be different from the MTU of local network to avoid packet fragmentation and so faster performance.By default, this Windows registry key does not exist in the registry, which when found, the computer assume this feature is enabled. Some software applications or some updates add in the EnablePMTUDiscovery registry key and disable it to harden the security of the system. When disabled, the registry key value data is “0″ by default in Windows Vista, and TCP/IP settings uses a default MTU size of 576 bytes for all communications and data transfers across remote networks, which may intermittently cause problems and unreachable packets.The above trick works on all versions Windows Operating systems after Windows 2000.

For more information read from Microsoft:You receive an error message in Internet Explorer 7: "Internet Explorer cannot display the webpage"